One thing that you need to understand about racing is that you need to win. Well, at least get the third spot because that is what matters most in any race. Besides, with the money that you will get there, you can rest assure that you can be in the top spot at the next race.
Drive your car as fast as you can till you reach the finish line. Try not to hit anything since it will slow you down. Grab the turbo icons as that will replanish your turbo. Use it when the bar is full. You get part of the prize reward after the race. You can use it to buy upgrades or for purchasinga new car.