There is no way you can change the driving aids in two player mode. Used to be able to change them on two player mode with the garage cars, but not anymore.
When you try to race in mutiplayer with you car from the garage it comes with the settings you set the last time you saved if you saved it with assist on then thats the way it will enter in multiplayer...
When you try to race in mutiplayer with you car from the garage it comes with the settings you set the last time you saved if you saved it with assist on then thats the way it will enter in multiplayer...