Was bored and thought up some other handicaps you could try. May not be as funny as the ones before. But here they are before someone else takes my fame.
1- Before starting, take all of your car's bearings, soak em in water, and then wait for them to rust.
2- Interchange your hands. Steer with the right, throttle with the left.
3- If its daytime, get a completely silver body so the sun shines in your eyes.
4- If its nighttime, get a completely black body so you cant see your car.
5- Buy a tyco, rip apart and use that motor
6- Take out the foam from the inside of your tires
7- Disconnect all of your shocks
8- Tape a plastic cup filled with water near the ESC, so it short-circuits if you make a mistake or someone hits you
9- Set your steering and throttle endpoints to 5-10%
10- Dont tighten your wheel's nuts hoping to lose wheels during the race
11- Take off two tires (one from the front and one from the back).