Your friend is not the best driver I guess? Because I was drivnig against same Cayenne Turbo(KIT) with my ex M3(e46,manual, 19") on Croatian autobahn last summer and he was almost two cars lenght behind me. Yes, I was pushing it all the way up(shifting at almost 8000rpm) but, he also floor his Cayenne Turbo(Kit) to the floor. I offer to this friend to exchange the cars but, he said to me that he do not know how to drive manual car fast(he also admit that he could brake my gearbox...)!