Easy wins
When you are at the start of a race, tap your opponents to lock them in as targets then shoot them until they explode. You can now take your time in the race and win every time.
Before you race, get a gun that is capable of a drive-by shooting. Go to the starting line. When the race begins, allow your competitors to get in front of you. Stay close to their cars, and keep tapping to shoot their vehicle. The car will eventually begin to burn and explode.