Completely offtopic- but the mention of Top Gear and pinewood derby in the same thing reminded me of something. YEARS ago (seriously probably 20 years ago, or more) I was in Cub Scouts. I got to do ONE pinewood derby. And while I did rather poorly at it- I remember one kid getting actually removed from the event. The reason? He had two small "figurines" as driver and passenger of his car. They weren't pornographic or anything, nor did they swing his car over the weight limit. They WERE however, live .38 slugs... and somehow his dad, who was standing right there, didn't see a problem with it.
Anyhow... so are we need to do loop physics... hokay.