If you are wondering what kind of tires to use in races, here is some advice. For street and cement races we recommend that you use flat tires. For a dirt or off road race you should use spiked tires.
If your car breaks down and it is an inexpensive car, it will have to be fixed. Probably the only way you can get it to work is to take it to a professional. Expensive cars are a lot easier to fix, but it will still be better to take it to a professional.
We learned that price of the car didn't matter. The car that won was worth about $30 and it raced with a car that was worth about $80. We think that the difference in the two was that one car was easier to drive and the other did a lot more moves but harder to control.