If you're talking about online play, june 7th's update will even things out. If you're talking about single player, just keep trying until you win. It is meant to be difficult towards the end, and the better you do the more the AI will try to run you off the road. So if you're in first place the entire race, it's going to be tough. Try just keeping up with the pack until the final lap, after that be as aggressive as possible and hope for a little luck. I know the last buggy race at raingod mesa was the hardest for me, but persistence paid off.