Warning: long post impending:
Where do I begin? Watch Dog's driving sucks.
On to GTA.
As with everything, i believe there should be the proper amount of balance. Car physics for players are literally completely different than NPCs.
Example: Im driving in a Primo (fully modded) and stop, the car behind me gets spooked out and runs into the back of me. I hold both the brakes and the handbrakes as hards as I could. The woman NPC behind me was in a Sentinel and proceeded to slowly push my car out of it's way despite my car trying so hard to stay stopped that the tires are smoking and I'm basically doing a burnout. She keeps pushing me for like a whole block, i get out, kill her, get in her car, which was still directly behind mine, attempted to do the same thing she was doing, and the Primo wouldn't budge. I mean not at all. How was she able to push my car a whole block with the brakes locked up but i couldn't do the same thing with no one in the car at all?
NPC cars have some sort of "freight train" physic, where their vehicles seem to have way more mass than ours, as long as an NPC is driving it. They can plow thru our cars (or multiple cars) from a dead stop; yet when we crash them we get halted or spun out like we hit a f*cking brick wall. This needs to be changed
Police need to be properly programmed as well. There is a video on youtube that shows how the police bumping into you from behind magically make your front wheels turn forcing you to lose control. That's bullsh*t - we'll just ignore the fact that police have some sort of Nos turbo boost and can catch up to you in anything while driving anything - the fact that they just make you swerve all over the place from tapping you is lazy programming. The police cars try to PIT you sometimes, I can live with that; it's realistic and practical, but that tap you once and the wheels start jerking needs to be fixed. Also I don't understand how a Police Van (stockade? It's the police variant of the Pony) can magically catch up to me and ram the sh*t out of me when normally that van is a slow POS.
GTA IV's driving was OK but the understeer in cars was extreme. The thing I like most about GTA IV's driving was the weight transfer in vehicles: In other words, car's actually felt like they had a suspension; unlike in GTA V where every vehicle is like a moving brick. SUV's and Trucks in GTA IV were more prone to rollovers, they need to bring that back to GTA V. However sports cars in GTA IV had too loose of a suspension. Like I said there should be balance. Sports cars and other vehicles should have tighter suspensions and handling, while Trucks, SUV's, and larger cars should be looser and have more body roll. For this R* would have to take a ton of time developing each car's handling, which I don't see them doing.
I feel like some cars are way to sluggish, like I understand that a 4x4 pickup isn't going to keep up with a Ferrari but it seems like a lot of vehicles were given very poor engine stats. Some cars are a nightmare to drive in tight situations being that they're so slow you'd probably be better off on foot. Once such car is the Emperor. I love the car, but can barely take it out because even when fully upgraded it's slow as ass. When I come across other players I'm quickly run off the road and shot up or blown up. I get it, a mid 80's cadillac doesn't have a lot of ups, but when upgraded the car should have generous speed. A lot of the trucks and SUV's, are extremely sluggish, and take forever to get to an adequate speed. It shouldn't be that way. I knew someone with a 94 Jeep Cherokee, that's an old little truck, and that truck had way more ups than a lot of the vehicles on GTA.
Don't even get me started on how exotics can take off roading better than most of the trucks and SUV's as well.
GTA V's driving is OK but has much room for improvement.
Drifiting? yeah, certain cars should be able to drift thru turns, since it's impossible to drift in GTA. Power sliding just takes a bit of time to master in certain vehicles.
anyways that's my two cents, or you could even say two quarters.