I recently took part in a 'No Holds Barred Pinewood Derby' at my church. I had elaborate plans for a car that would use some sort of spring-loaded arm to knock the other car off of the track, but in the end I went with a simpler design. Actually, I forgot when it was going to be and rushed to just get something done. Luckily, almost everyone else was in the same boat.
As you can see, my car is the block of wood from the kit with a brick gorilla-glued to the top. I named it 'fast,' but also toyed with the idea of 'heavy' or 'rough.'
I was doing pretty well, but then I decided to lubricate the wheels with a little oil that someone had brought. Some of it seeped onto the nails/axles which caused them to slip under the weight of the brick. By the end of each run, the wheels looked like this:
I ran it one more time after the derby was over and one of the wheels came completely out causing a pretty horrific (for a pinewood derby) crash.
In the end, I was beat by the car with the monkey wrench duct-taped to the top and the car with the wind-up accelerator. I did win the following prestigious award, however: