Wow...all you guys are making me jealous.. I have an 07' with not even 5000KMS on it, and I'm lucky if I get 475km to a tank.. I avg. city/hwy 8L/100KM (sorry for the metric USA'ers).

What HP gains do you estimate you achieved? Also, do you mind sharing the cost of the parts? I'm assuming that is aftermarket, and not provided by GM performance. Also, that would probably be something you want to do AFTER warranty has expired no doubt?