I've got one off eBay. It's good but you need a pretty flat road to get sensible results. Also, the standard suspension on my Cinq' allowed too much pitching on acceleration and upset the G-Tech. All OK now I've fitted an Apex kit though. Check out:
a mate at work is gonne lend me his at some point. I would buy one but do you have much use outta them once you've recorded your 0-60 and 1/4 mile times??