RE: RC games, when bashing gets boring
Have an uphill race where anything goes, and tie 1 small balloon to the rear of your trucks and if your ballon gets poped before you reach the top of the hill then your out of the race. Don't just make the race to the top of the hill but rather back down too.
Have the balloon poping contest with teams.
Have wheelie contests to see who can ride theirs the longest distance.