With Plastix 1.6.0 (and 1.6.1), you can now build functional race cars, mechs that dance, and misbehaving school classes. This is all accomplished with the new scripting API in the Properties menu. There is a tutorial for how to use it in the info section on the title screen. Read through it to start coding!

Also check out the race car building guide I made in the community. It makes use of simple scripts.