Mousetrap cars are fun to build and race and they make a great 4-H project.  All 4-H members 8 and older are invited to race their mousetrap cars in a distance challenge at the 4-H Makers Expo. 

Download this simple guide on How to Build a Mousetrap Car or view this Instructable to get started.  It uses simple materials like cardboard for the car body, CD's and rubber washers for wheels, a mousetrap, some wooden dowels and some string.