At the start of the race, get out of your car and go to the nearest corner that has cement blocks. Grab the cement blocks and create a barrier in the middle of the road (stack them if possible). This makes it almost impossible for the other racers to go past that point. Shortly afterwards they will all crash and pile up. Once all of them are piled up, shoot the gas tank of one of the cars to start a chain reaction that will kill all other racers. You are now the only one remaining in the race.