I really hate having to write reviews like this. This one pains me even more because it's something I'd actually like to do. I could have easily given it a really high rating if the "creator" had simply done the right thing. But he didn't. In fact, I've spent several minutes pondering what rating to give this product. For the moment, I've just decided to give it a median rating and hope that everyone will read this review to find out my reasoning.

What we've got is a variation of Dick Koornwinder's "Koornwinder Kar." To the best of my knowledge, Dick Koornwinder came up with the idea. The Cesaral Lego™ Car produces the same basic effect (it stops rolling at a certain point in its trajectory). As the name implies, this version has car made of Lego parts.

Using a Lego™ kit makes this more interactive than the original. Audience members can help you put the car together. People really enjoy this.

The problem with this product is that Dick Koornwinder isn't mentioned anywhere in the promotional materials or instructions. This is, quite simple, inexcusable. Even if Cesaral created this in isolation, it wouldn't have taken long for someone to point out the original. The documentation is a Word document that can be changed at any time. Yet there's still no mention of the original.

So you have to decide. It's a good twist on a great trick. But the creator apparently refuses to acknowledge the heritage of this effect. I'm still trying to decide if my moral convictions will let me perform it. You'll have to decide for yourself.

UPDATE 2/23/2012:

The creator recently emailed me the following:

"I wanted to inform you that now the manual says:


Effect

A toy car (Fire car) built by a spectator with Lego™ pieces finds a freely chosen card. The fire car stops when the spectator pushes it next to (or on top of) the chosen card.

The original effect was created by Dick Koornwinder and is called the "Koornwinder Kar" (It was done with a wooden car)."

Since he has now given proper credit, I've changed my rating from 2.5 stars to 3.5 stars. He has done the right thing and I want to honor that, but I still believe this type of research should be done before putting a product on the market.