Open steam. Launch beamng. it gives you that little white menu. instead of clicking "launch game" click "support tools" and then click "clear cache" if you need pictures tell me and i will include them
Go listen to the car in the game The sound is based off a Dodge Viper V10 I did not make this choice I only wanted the car to sound vaguely like it did in the game even if it's really stupid and inaccurate