I know this is already a feature of the game, just my idea is a improvement upon it. Basically, it would be nice if the DSG farts for certain cars sounded more sporty, or if a mod could be made to improve them as I have no idea where the sound file for the "farts" is kept. Here is a video of what would be cool if implemented; Another couple things that could also be implemented by the developers is a modern hot-hatch, launch control and parking sensors with backup camera system. Maybe the ability to open and close door's through a menu as well.
I was suspecting that it could've been the sounds of the cars changing gears. But why call that farting? So weird.