@LukeAlmighty The only reason it has those serious issue is because the developers designed it with consoles in mind and tied the physics to the frame rate, and R* is too lazy to fix the issues that plague GTA 4's PC port because they want tweens to buy GTA5 and shark cards instead >_<.It's a shame too because imo GTA 4 has a definitively better story and the rag doll physics are better to.
With that said the PC port is a pain in the ass to set up had to use DXVK .dll convertor files and use a bunch of launch flags to get the game to use the full 4GB of system memory it needs (32-bit app) and lock the frame rate to 45FPS since the engine becomes unstable and has game breaking bugs if it exceeds 48FPS.