Dinan upgrades are designed to make any BMW a more powerful/track ready vehicle. The ideal application (from the mouth of a dealer/certified installer) is for a 3-series wannabe M3, 5-series wannabe M5, etc.

The X3 is not a track car, nor a performace car--in fact, stage one Dinan for an X3 is practically insignificant (only increases the the jumpiness of the throttle).

My suggestion would be to beef up your X3 with some exterior mods, like aluminum running boards, aero kit, etc. The Dinan company puts together a sweet package, but you own an SAV, not a coupe.