The Car Add on for Zhu Zhu (Go Go) pets is fun, and funny.
You need to clip the garage together, which is easy, but it can un-clip all too easily, meaning you have to fiddle to get the doors back in again. A minor niggle. I just wish, once clipped together it stayed clipped! Tempted to tape the thing down.

Better than real hamsters though - they don't drive cars :)
As with all these add-ons the hamsters get a different "code" from a series of ridges in the floor as they run into the garage, which means new noises from the little blighters.
Clever.