Re: Actually that's rather a non-issue here...
I've actually been thinking about building one. CAN bus isn't really that complicated. I figure it's only a matter of time until all insurance companies require them (or make rates so high, you can't afford insurance without using one). I would never install such a thing on my car.
I could move offshore, and sell them on Ebay. I'm really surprised no one has started doing it yet? I would have thought some Chinese company would already be making them? All you need is a simple dongle and some software for the PC.