i have noticed that the engine sounds are all the same for the vehicles. and have noticed you have one engine sound file for the game. I was wondering if you could program individual engine sounds for the specific engine. also it would be cool to see different tire sounds for that specific type of tire, like if you had 4X4 tires they would make a roaring sound on pavement .
I've successfully implemented what you were looking for http://www.beamng.com/threads/9211-TUTORIAL-Unique-engine-sounds-for-vehicles