I think these Pinewood Derby schematic t-shirts ($7.99) available from BSA National look pretty cool, and I bet a lot of boys would get a kick out of having one.
(Unfortunately, the graphic at scoutstuff.org is pretty small and doesn’t show much detail of the schematic. If I can get hold of a larger graphic, I will get it posted.)
These are only available in youth sizes, but I know a number of adults who would probably enjoy a shirt like this. Link
