I appreciate your responses. I am happy that a BMW dealer installs these mod's and that it is still under BMW's warranty. I am probably going to do the throttle body and the exhaust next. You may have not purchased your X3 to go fast, but I will tell you that it is built by BMW to handle alot more power than it comes with stock. Ask the guy I was following in the VIper on 95 on the way home from the mountains. It was great.