I personal would like to see hydraulics for low-riders and they should add some more low-riders, also a clean version of the Voodoo.
Add more proper choppers like some from TLAD DLC from gta4 and make them more customisable and be able to change the forks and more types of fuel tanks etc.
Be able to make your BMX/ Cruiser like the one in tyres Gibson film baby boy.
be able to buy and personalise the condos in chumash.
Add the Spitfire from Sanandreas.
Put in the heists !!!!
Being able to buy big buildings for your crew and your logo goes on the sign and you name it what you want and customize.
Add lots of different cars with but loads of mods.
Add different skins for the monster truck.
anyone else think of some stuff to add, so we can get Rockstar to see !!!