I just tried it this weekend and so far I love it. I spent $650 delivered on this one: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=170369064952&ssPageName=STRK:MEWAX:IT and it arrived from Hong Kong by DHL within 5 days. The only thing it needed was a special key code to unlock the pre '07 Smart models and that cost another $30 from JCRecordings.com.

On my first car a 2005 Smart cdi originally from Canada, I had removed the seats previously and happened to turn on the ignition which set the airbag light on. I couldn't reset it by just disconnecting the battery. 10 minutes with this tool and I had it erased. A mobile airbag service wanted $100 to do this and may not have had the right software anyway.

On my second car a 2005 Smart gas turbo originally from Mexico, the odometer was showing ------ and the other display features were inop plus the tachometer didn't work. The instrument cluster may have been replaced previously and nobody in the U.S. had a way to code it to the car. In less than 30 minutes I had the odometer display coded and showing the correct kilometers, as well as the fuel gauge, temperature gauge and transmission gear indicator working, then I coded the tach and it was working again too.

Overall I'm very pleased with it so far. The only problem is it takes like 15 minutes to "bootup" from the time you turn the computer on to when you are ready use it but that could be a function of the computer's specs. I can't wait to try it on my '94 E420 with an inop cruise control and ABS light on and buy some late models needing some work.