I have something cheaper. My nephew sits in the car and follows instructions, and I don't even have to feed him...

(The bar clamp mod is a great non-relative-reliant solution. I just wanted to be the first one to make that joke. And I do feed the nephew. He's a good kid so we get him ice cream, so he's actually more expensive since I have the per-use expense instead of the one time expenditure.)

I love the economics of this kind of thing.