These cars are a huge hit with the boys. They don't take a lot of time and are a lot of fun.
Start by cutting out cardboard circles for the wheels.
Cut a square out of the top of the toilet paper roll for the seat. Glue a small cardboard circle in the front of the cut-out for a steering wheel.
Using fasteners, attach the wheels to the car. The kids can then decorate their cars any way they want.