I tested it on Test Area 54, and it can do some jumps on gravel, but it did get damaged on the other half of the trip. OT:
Made the jets super powerful and have infinite fuel... this is what happened: Um... This kinda stuff happens aswell... It gets much worse too:
Invisible suspension + Hirochi Sunflare = Hovercar One of the smartest ideas I've ever had, and now the Hoverside has a contender.