Customizeable Car Track

This is a customizeable set of car tracks I created for my son's Cars 3 Mini Racers.

Customization tips:

* To set the `track_width`, make sure to add some margin to the width of the car so it can go around the curves. +10% worked well for the mini cars I designed these for.
* To set the `track_base_height`, consider whether you're going to use on a hard flat surface or something softer like a blanket or table. Thin (1-2mm) works great on a flat surface, but you'll want thicker tracks (3