Pinewood Derby Car Painting Stand

This is my first from-scratch Blender project, as much as learning to use Blender as it is to produce something useful. This is a stand for painting a pinewood derby car, before attaching the wheels. It slots into the grooves on the bottom of the block of wood.

I'm attaching the .blend file in case anybody wants to tweak the design; *please* feel free to provide feedback if you do :).