rctruckracer: you said there are no 'measureable statistics' for bashing? how about... distance jumped? air time? stunts? maximum speed thru a certain point?the fastest from one point to another (yeah maybe thats called racing too)? there are so many things you could do ....
how about 'freestyle' points ala monster jam? trying not to roll over on a non-race tuned mt can be quite tricky...and having a limited time to do all the stuff you want would make you wish there was more time
one person could start first on a routine thru the area, the rest would copy and try to better him ,everyone else would then try to follow that... and the person who no one else can immitate would clearly be the winner....
one person could have their truck a few yards away from another truck, and the goal is for one truck to get close enough to the other, or if your willing to risk it, actually have contact between the two...
instead of investing in a track, you could instead pick up a couple of random things and improvise... if you find a ball, for instance , you could turn it into a sport... or if you find something thats easily broken, you could smash your trucks into it...once its crumbled to pieces, drive your trucks over it...