In Reply to: Anyone has a front bra on an M3?(more) posted by Yella on May 12, 1999 at 11:23:58:
They can't be left on for extended periods of time. They will abrate the finish at the contact points and the paint fade at different rates. Also, you're not supposed to wash the car with them in place. Mold and stuff will form under the bra. Also, debris can get trapped underneath, possibly damaging the finish.