In Gta V They should bring the gangs back, for one thing. I liked the ability to be able to grab some hommies and go shoot up the place. Sure there are mods that allow you to do this in iV but it's not the same as grabbing some members of you're gang and and going to an enemy gangland and shooting at random. Just not as fun.
In Gta V they should bring back the ability to buy houses. What should we do with all the money we get? In GTA V i have 600k and I'm not even finished with the storyline missions, and i have NOTHING to spend it on. You should be able to buy Cars as well. I feel like just walking up to a random car and taking it with little to no repercussions is just too unrealistic. It doesn't suite the new graphics engine and the level of realism that Gta IV brought to the series.
In Gta IV when you get arrested for committing a triple homicide, steeling 4 cars, and killing countless police officers, you're punishment is either getting seriously injured and waking up at a hospital with 10 grand in medical bills with nothing else to show for it, or you get arrested, and pay 10 grand to the police and lose your weapons. For me it seems all too easy. If you've ever played the Jailbreak mod for iV i think there should be something along those lines for being arrested. If not for every time, at least for being arrested at 4 Star++ wanted ratings. As for getting killed, you should at least lose you're weapons, if not more money.
As for the game engine itself, they should redesign it to work with PC. They just ported the code from the console to PC and altered it to make it work (As far as I have read, don't quote me on this) which resulted in a terribly laggy game engine that requires the equivalent of a supercomputer of sorts to run at maximum graphic with a 60+ frame rate.
For the car driving aspect i believe that the engine for that is near perfect. The cars drive realistically (Minus the fact that you can crash head on at 60 MPH and keep driving) what with the way they sway back and fourth when you turn. They handle well too. The only problem with the driving aspect of the game is they way they deform when they crash. For the next Gta they should implement DMM technologies for the car deformation.
Thats an example of Wood and glass.
Dmm deforms/breaks breakable objects ultra realistically and it's different every time depending on the impact force and material. Perfect for car crashes yeh?
Heres a Lucasarts demo.
Well thats my idea for the base of Gta V. Comments?