Well, I see them on eBay for BMW

$299 + $20 shipping...

Here's an informed write-up http://frontiernet.net/~dbipes//sprintbooster/SprintBooster.pdf for those that want to see tech results...

BTW, there are lots of posts on various forums by Mercedes Benz and BMW drivers about how they really like this product.

__________________
2008 X5 4.8i | Wheels: Summer> style 336 20" RFT; Winter> style 214 Ferric Grey 20" RFT | Aero kit | ESS E-Flash tune | V1 | LCI Rear Tail Lights | Coding completed | Engine replaced at 90K