While looking for a Pinewood Derby Track to make for our Cub Scout pack we found the www.nerdyderby.com track design which was very modern and a clever design to be made in a home workshop from plywood.
The Nerdy Derby track files are located here.
We used this track design concept and modified it to a 4 lane BSA size track.
For a cheap timer using an arduino uno we used,
For tracking the race lineup and results we used,
These files are the PDF drawings, DXF files and Solidworks files for easy viewing.
There is also a drawing/DXF of the drilling template jig to make manufacture easier.
The approximate cost to build a track for the main hardware is $400.