Personally, I think all the enhancements Dinan did to my 03 X5 make the car handle better and reponse more dynamic:With the chips and throttle body, the x5 has more torque and power both @ low and hi rpm (you will notice more @ hi-rpm). And I also notice the engine reponses smoother @ low rpm. The D-exhaust is awesome, both sporty Dinan exhaust sound and more horsep. Also installed the camber plate which provides excellent handling @ cornerning. I really appreciate what Dinan did to my x5 and I highly recommanded.