Re: Brera Alloys
There are two Breras in my area with these 17's fitted. One looks reasonable, but I think it has been lowered so the wheels appear to fill the arches better.
IMHO even the 18's on the Brera are only just large enough and I am intending to fit 19's in due course. So I'd hold out and find one you like, or use it as a bargaining point.
You can buy 19" Ti alloys from Partsworld for around £800 so if the car is right, then it might not be too painful to fit the larger wheels.