Hot Wheels Custom Motors Starter Set: Go from street car to race car to monster machine. This assortment lets kids to build and race their very own customized Hot Wheels cars in a matter of seconds. Each 1:43 scale vehicle has realistic details and comes with 2 sets of wheels. The interchangeable, modular system features easy, snap-on parts – with more than 15 parts for over 100 combinations. Build your collection – and the custom possibilities.