Back in 7th grade my co2 car was the fastest in the whole school. We had to carve ours out of wood. I made mine looks so BA.
The teacher had a really nice co2 car that beat everyone who faced it. I beat him handily. It was a whole lot of fun. I went to the extent to put graphite lubricant in the axles. We didn't have speeds and I can't remember the time, but it was really dang fast.