Die Cast Car Wall Track Return

THIS IS A UNFINISHED WORK IN PROGRESS! I'm sharing this unfinished work in the hopes that somebody with more creative ideas and CAD skills can continue this journey. The goal of this project was to take Hot Wheels tracks that I had mounted to the wall with brackets and create a curved track that would allow the cars to then turn and come back the other direction on the wall. The challenge I faced when trying to come up with the geometry for this return track, is how to compensate for die cast vehicles that would be traveling at a variety of speeds. Currently this track works for cars going slower, if you have a very fast Hot Wheels (die cast) vehicle it will fly off the track. Current items on my list of things too improve. Printability - due to the geometry of several track pieces, and the small connector parts to connect them, support is required for all of them and minimizing that would be ideal. Connectors - currently little pieces to connect each part of the track together are