Why not just print your Pinewood Derby

A printed Pinewood Derby car? Yes please. Tho I don't think that one would run on a standard track.

Actually, would anyone believe me if I said I had this idea before? I mean, it's got to be a common idea. My thought was I wanted to make a small CNC router and have the neighborhood pack use tinkercad to design their cars. I wonder if I could get a fork of Tinkercad that would define a maximum space?

But that's on my long (ie, probably never gonna get to it) list.