I think it would be a really fun. However, I think it's incredibly stupid and dangerous. There would be no way to warrent who could participate, etc... Or when a safe time to do it was.
Too many people would go overboard and eventually hurt someone. HOWEVER, if there were penalties for going over the speed limit by X, etc...
I think it should be like a motorcycle enduro race. You basicaly have a chart with times. You have to get to the check points in X amount of time. You lose points for being early, late, etc... You don't know where the check points are exactly so you really have to navigate and compute where the check point will be. A check point has to be every X miles, but there is a bit of leeway. Then you have technical sections where you have to complete them as fast as possible. I've raced these and they are FAR more fun than just racing and also take a fair bit more skill
