I have a 4.8is I installed on. I did not use the fender flares that came with running boards. You have to buy new flares if you have 4.8is.

Check part #s in this thread
http://www.xoutpost.com/bmw-sav-foru...ng-boards.html
Another thread for 4.8is
http://www.xoutpost.com/bmw-sav-foru...explained.html