AA stageII turbo on a m3 is amazing. no lag what so ever. its almost scary how fast it is. I have a 325 AA stage II turbo and this is awesome This weekend I test drove a 1999 528i automatic with a mectech turbo installed. The turbo was the M3 setup with slight modifications to fit the 528. Very clean install by the way, looks almost factory. The car didnt seem to have the pull like the M3 down low but at higher speeds seemed to be rather impressive for a 2.8 liter, also the fact that it was a stage one. Does anyone have first hand experience with an M3 with the Mechtech? I would expect the M3 to be more responsive and quicker being all the differences are in our favor. I am considering the stage 2 with AA Gen III exhaust, lightened flywheel and sport clutch.