My younger brother and I used to race Matchbox cars down one of those PlaySchool slides for my youngest brother. We would have 5 sets of qualifying heats of five at a time, removing whichever car made it least far to the next part of the qualifying until we were down to one car, which made it to the finals. After we had five cars for the finals, they raced off in similar fashion until we had a grand winner. We each took ownership of different cars and had a few neutral ones thrown in there as well. You could usually count on about 4 or 5 to have the best chance to win it all. My parents eventually replaced the floors that had had these cars repeatedly banging into them.