Yeah, the main thing that would keep interest is different game modes, (and ofc mp)
You could have demo derby
Trick Fest
Race
Survival, (dodge objects as long as possible, last player alive wins)
Drag, (Players design their own vehicles and test em out.)
Custom Track Designs
Custom Car Designs.
Also, REAL AIR THAT PRODUCES DRAG.
I will make a little diagram thingy of my idea for car making.l