You need to create "Objects" that have an Action attached to them, in Nic's code, the action is platform_action(), and it serves to rotate the object it is attached to, referred to within that code as "me" or "my".

The code also creates 4 "car" entities around the rotating main model, which are placed by the code, so don't need to be put in in WED - just place the main circle, and attach the Action, with the Properties (bottom left of WED - select the object, find Behaviour, then use the Open icon for the action to use.)

You assign a Script file to the world, in WED under File-Map Properties -> Script, and then actions in that Script file will be accessible to objects in WED.

Have fun, and if you need help, PM me - I'd be very interested in this sort of project. I use sketchup alot and am thinking of setting up a "simple" procedural town generator with sketchup models.

edit - oops, didn't see the second page - you might be past this advice.

Don
have a great day