as you should know, you can freely leave your starting vehicle and even steal another from the road or even your fellow racers....
well start a GTA race on Arms race with traffic on... Boom!
you can steal a jet and use it to race! i just did this with bicycles solo to try it, its not likley to win easily against super cars since its pretty easy to overshoot the checkpoints but you can blast anyone or anything that dares to get in front of you =P
imagine if you find a tank during this!