This is an updated version of https://www.thingiverse.com/thing:3470800. I've added a tab to the top and corresponding slot in the bottom. I've also adjusted the tolerances on the interlocking parts, which makes them fit together better. Also included a reversible wheel chock insert, as I notice a lot of my cars have wildly different wheelbases.

As with the previous display, turn this on it's back, and you won't need supports.