These are in no specific order just as I think of them while I type.
1) All weapons and cars from online sold offline on websites. Actually ALL cars and weapons in the game available to purchase in single player.
2) Non-claravoyaint cops. I'm tired of cops being tipped off by animals, or going to where I was and automatically know I am hiding somewhere else. Let them search a zone the higher the stars the bigger the zone. Extend the amount of time they search but let them look around, not just automatically know where I am. Unless someone sees me (a citizen) go that way and reports it. Have roadblocks on each road out of the zone at higher star levels and no matter what if you have no gun let them arrest you at all but the highest cop level. Level One: Arrest, Search Area: 100ft circle; Level Two: Mase and Arrest, 500ft search zone circle; Level Three: Taze and Arrest, 2000ft search zone; Level Four: Shoot to Kill if armed, 1 mile search zone; Level Five: Straight up you gotta Die!, 3 mile search zone. Have more intensive searching in the zone and very light outside the zone. Stop having the cops randomly insta-spawn in front of pay and sprays, Stop having them insta-spawn directly in front of you constantly at higher levels. If you barricade in a building and keep killing all cops who come in have them hold the perimeter until you come out and then smoke you, or throw in gas and knock you out. Also have all vehicles have the same speed and stats no matter who drives them. I find it funny if I drive the fastest car in the game but not only can the cop car keep up but it can put on a burst of speed to ram me! Utter crap! I also find it funny that as soon as I turn around there is a cop car not 50 feet from me with officers getting out shooting at me.
3) Be able to drop weapons, or if you have to keep all the weapons on you, have it so you can choose favorites that always are at the top of each type of weapons list.
4) When I steal a car and change it's plates and repaint it it should be mine. Don't let cars we park in garages disappear if they have been chop-shopped. This whole list is because I parked a Dukes in Trevor's trailer's garage and went to drive it and it was magically gone after having been in there for over two weeks real time and multiple uses. All of a sudden... presto... gone!
5) Have suppressed weapons actually be suppressed or reduce the distance a scream from someone dying can be heard. There is no real point to suppressors in V because if you shoot someone everyone else seems to hear them die and panics and runs. And if you shoot a cop in the head you shouldn't get an instant 3 star.
6) Even at the highest cop levels still have civilians around until roadblocks are set up. And if you get past the roadblocks have them return. It is bull that when I start killing cops everyone is just... poof... gone. Not only that all the parked cars seem to disappear.
7) Put a speedometer on the HUD.
8) Make the cars use gas and make gas stations useable.
9) Have more than two car washes on the map and have them spread out.
10) If you are going to have multiple store chains, have them sell different stuff. Binco and Discount stores both sell the exact same stuff. Pointless.
11) Have different looking people running the different stores instead of the same chick no matter which Binco store you go into.
12) Let us eat at restaurants again and food vendors as well as pop and chip/candy machines for health. Let us eat and drink even if our health is full. Let us buy drinks in variety stores not just munchies.
13) Allow us more idle time stuff to do. Sometimes I would like to just sit on a park bench and watch the world go by. Also the roller coaster and ferris wheel were a joke. Having more than one place to play darts would have been nice too. Plus why not add basketball, table tennis, bowling, pool (both the table and the liquid medium, only more useful than the tiny ones in V, darts or add video games back in again.
14) Increase the speed cars can go. I drove the Adder with all three guys but the top speed I could do was something like 130; unless I used Franklin's skill. A supercar should go over 200mph.
15) Have AI cars randomized by the parts they have on them, not all just stock. I liked that you added some special cars sitting near the one Pay n' Spray in downtown LS and some sat in various spots around the city but they should also be driving around. And not just the high end cars. Joe average AI should be able to put different rims on his car.
16) Have more interiors. Let us rob houses again, Let us hang out in more bars than just the strip club. Let us hang out in restaurants and coffee shops.
17) Give us bigger garages to store vehicles in. I was hyped about buying the garages for my guys until I found out they just held 4 cars. The hint boxes gave the impression you could store infinite amounts of vehicles in them.
18) Have all weapons, gear and cars available to buy from the start. If I want to save my money to buy an Assault Rifle instead of just piddling around with a low damage SMG I should be able too.
19) Add more jobs to make money. Let us get jobs instead of having to steal a taxi. Let us go in and get a car assigned. Add varying jobs like bouncer where you have to check IDs and kick people out. Or a delivery driver, for packages or vehicles. Or Repo guy or Bounty Hunter, or Tow Truck Driver with more than six missions that when you do them they are done. Let us make money at them.
20) Either have stop signs or stop lights. Make up your minds. Plus have one side go at the same time and then the other (ie north/south then east/west). I mean all cars and pedestrians. Have the lights stay green a little longer, but let me not have to wait five minutes at a light to get through. Synchronize the lights so when one is green in one direction all lights are green. Have more lights green when I come up to them. I like to drive like I am in real life but it pisses me off when EVERY light I come to in my route is red for me. And when I stop no one is moving at all in either direction.
21) All convertible roofs should work. Cars with automatic spoilers should work as well. Also if I turn my lights on during the day leave them on instead of automatically going off after 30 seconds.
22) Slow the global clock down a bit. I get ticked when I take a walk and go six blocks and it goes from 1pm to 5pm. I know that time has to run faster but it doesn't need to be that fast! It takes me out of immersion when I walk around the block and it is midnight by the time I get home.
23) Let us rent motel and hotel rooms to sleep in, instead of always having to go home to sleep.
24) Have a choice for vehicle music but NO background music. I love listening to the radio but I hate just random background music when I am walking around. I would like to hear the sounds of the city, not BG music. And it is a bother to turn off music everytime I get out of a car and then turn it back on when I get back into one.
25) Give us more things to do inside our houses. Not only drink a beer but eat a sandwich or something. Not just watch tv but play video games. Or turn on a stereo and listen to music.
26) Give us things that we can keep doing after the main mission is completed so we can keep feeling there is someting to do with the game besides just killing sprees.
That's all for now if I think of more I will add them.
27) The ability to customize your car plates without using a phone app.
28) If their is a subway or el-train in the new game have it go faster than the one in V, that thing is useless as viable transport across town. SO SLOW!
29) When you tell the taxi drivers to hurry up they should drive like the ones in IV. They knew how to get somewhere fast, and didn't get bogged down because there was a car beside them at the intersection or a car in front of them on a two lane road. Let them drive like the people you scare or intimidate do. They drive through anything.
30) Do a better job of traffic diversity. Nothing destroys immersion like 10 of the same SUV all around you, or seeing the same five cars all over a certain area of the map.
31) Some of the taxis should be dented up and those drivers should drive crazy when you get in their cars.
32) Bring back police foot patrols and have random street crimes where they chase or call in reinforcements.
33) Have emergency vehicles as traffic as well.
34) Let us sell cars in solo as well. And let us choose what is our characters main car that they are always in when you switch to them.
35) Have stubble look like stubble. I played PS3 version and PS4 version and the stubble on PS3 looked more believable. The stubble on PS4 just looks like black makeup on their mouths and chin.
36) Pedestrians should react to cars horns when a few feet further away than they do now, which is when you are almost on top of them. Then they can either freeze or try to dive out of the way.
37) When I leave a personal vehicle somewhere it should stay there until I get it or have a driver company you can pay to put it back in your garage.
38) If my character has a family and I switch to that character and watch him drop one of them off I shouldn't be able to go to his house and watch the person I dropped off four minutes ago to go shopping having an argument with another family member at home. The family should have eat, sleep work habits like the rest of the population should. When you go home at 4 in the morning they should all be in bed, unless they are partiers or night owls, but then they should sleep all day.
39) If you are going to have a load into interior at least have it match the exterior you see in the world. Going into Michael's garage where there is a door right beside the garage door and you get inside and the door is on a different wall was immersion breaking.
40) Have the vehicle my character drives as AI vehicles as well. I find it odd that I own the only Buffalo S in all of Los Santos, or whatever thing Trevor drives. You see Michael's car at the Simeon dealership but you never see anyone driving one.
41) Have different levels of vehicle lighting. If the car has fog lights and roof lights have first press turn on lights, then high beams, then high/fog lights, then high/fog/roof lights and have each level brighter and further out.
42) If the next mission is a few days later have it pop up a few days later instead of immediately. Have the option in a save house to advance to the next mission day in case we want to just do other things. Tell the time to show up for the mission or after the mission briefing have them say "This will be a night job so we will wait." if you go to it in the day instead of automatically advancing time.
43) Let us buy a motorcycle helmet instead of just getting random ones when you get on a bike. If Franklin can magically pull over 20 different weapons out of his pocket why can't he pull out his favorite helmet?
44) Let solo customize their cars the same way they can in online. Some people don't like to play online because of the toxicity of others but like to play your game. Let them have the same perks and rewards as the online people. I played online for about 20 minutes and quit and never went back because I was level 1 and some level 147 guy kept killing me for no reason. I had just started the game and he followed me around killing me. When I went invisible he just blew up my car and I couldn't pay the insurance to respawn it so I quit.
45) Like putting on a motorcycle helmet when you sit in the car a couple seconds before starting you should put on your seatbelt.
46) Cars should be sold on lots like car dealerships. We should be able to buy and sell vehicles there, if they are ours. Maybe have a chop shop where you can sell stolen vehicles.
47) Have drunk drivers and road rage incidents between AI vehicles.
48) Bring back car jackers that try to grab AI or even player vehicles when stopped.
49) Have the scuba tanks like the parachute so that you can buy and carry them. Have a limited time amount of oxygen in them so you have to buy a new one.
50) Engine upgrades should increase top speed not acceleration.
51) The ability to delete phone contacts. Especially those that are of no use anymore.
52) Keep the cheats in the game. A lot of companies are getting rid of cheats but they make for fun screwing around. Also keep them in the phone like in IV once activated. Maybe have them activated after the game is completed and a player starts a new game so they can cheat if they want after completing the game normally.
53) Let us put tattoos and hairstyles on our characters BEFORE we meet them in game so that in the first cutscenes they look how we want them to in game.
54) Make riding the bus an option of alternate mobility.
55) If I help the police I shouldn't get a wanted level.
56) Gangs should do drivebys of each others territories and have big gang shootouts with the cops coming and fighting them all.
57) More TV shows to watch.
58) Don't add weapons to my character. Let me use the ones I have for a mission with the ammo I have. If you want me to get a specific weapon for the mission make it part of the mission. Like when Franklin gets the shotgun or Trevor the sniper rifle.
59) Should be able to roll all the windows down on a car. Like using the convertible roof.
60) If a road has a dead end don't have a hundred cars coming from nowhere on it. The road to the top of the Vinewood sign would have been awesome for drifting corners except you put irrelevant traffic on it.
61) If you give the character a vehicle to use it should be theirs for the rest of the game. Such as Trevor's Blazer you only see during one mission but has a personalized plate, or the Cargobob he steals and paints his company name on.
62) When I spawn at my house put my car in my laneway, not on the road or across the street.
63) Don't finalize every thing we click on in the garage. Let us fiddle with the look of our vehicle and charge a total at the end.
64) Cabs should stop closer to you.
65) Should have bullet resistant glass for all cars. Have different levels that take more damage before they shatter.
66) Should be able to sneak into any authority sites, like military bases, without automatic most wanted levels and insta-spawning missiles from nowhere.
67) Planes, especially military, should have flare and chaff countermeasures.
68) AI should drop money varying by their class. A rich person should drop more than a homeless person.
69) Allow ATMs to be blown up for money.
70) Have random events happen all the time not just once and they are gone (ATM robberies for an example).
71) When I kill someone or blow something up in the middle of nowhere the police should not be alerted.
72) If animals on the side of the road are surprised by my vehicle, they should be surprised by any vehicle. Also if an animal will attack me, it should attack anyone.
73) If you put tanks in again they should have a slower fire rate.
74) Let us sell or throw away the clothes we don't want to use.
75) All vehicles should have one specific spot on the map they always spawn so you can find the vehicle you want, if you are not going to sell them all on lots or ingame online.
76) Jets should fly MUCH faster!
77) Cannon shells should do damage much further out.
78) Missile lockon should be further out as well.
79) The mini-mission where the prisoner steals your car is bullcrap. He should stay on the map until you get your car back from him. As soon as I got into another car he disappeared. I was so disappointed I didn't have the opportunity to hunt him down.