Hi sorry a bit long to get a reply have you baught your tires yet ... according to the sticker on the inside of my door 235/40 17's are the widest that Mr BMW recomends but with a bit of wheel arch rolling .... I have 225/45 17's on mine (they were on it when I baught it) and there's not a lot of clearance left. Maybe someone can say if they have any bigger.