I want to add some zip to my 2004 X5 3.0i but there is nothing available that I can find except the air intakes and expensive exhaust systems that do not do much. My question is why can’t I use the ECM programmers, headers, turbos, etc from the BMW 3 series that have the same basic engine? Is the X5 3.0i engine that different from the engines in the 328 and 335 series? Those engines have tons of mods available. If there is no real difference then why isn’t anyone exploring those options? My BMW dealer says there is no compatibility but I do not believe it. Any thoughts?