Speaker Mounting Brackets
2006 BMW 3 Series
Crutchfield Customer Review (What's this?)
They fit well. I added a flat steel fender washer for more surface contact to hold the bracket in place. The universal brackets supplied by Alpine with the 6.5" speakers do not work on BMW.
Pros: They work on the weird BMW triangle speaker mount points.
Cons: Not sure if it's a "con" but you can not reuse the BMW factory speaker baffles. The factory speakers sound terrible because the baffles. They don't allow the speakers to produce a lot of bass. Be sure to put sound deadening material on the back of the door panel because new speaker without the baffle will sound great, but there will be some vibrations at high volume.