aah yes maryland/nj really close to salt water,and salt on the roads also, both of those are not good on any part of the car, basically the salt can eat through paint and leave those white dots, aluminum is un protected so it happens faster, salt in the air/water will carry more electrons which in turn will corrode faster then non salted water. so only way to fix is sand,repaint (for painted pieces) and use a stainless wire brush or stainless steel wool(i suggest this as if you dont get all the tiny steel fibers away they can rust and leave staining or even worse depending on location) sorry your car is doing this, another way to prevent it is frequent engine wipe downs(after a deep clean of course) and that will help greatly with the corossion. as i said its happening to my 94 celica as it was a NY car untill about 2005, then came down here untill now. i always try to take something negative and try to turn it into a positive like "my valve cover is corroded man that sucks, on the good side now i can remove it and paint it the color i wanted!". hope this gets worked out for you, might help to browse the bmw forums and see if this is a common issue(no matter of location) or if its due to engine not being cleaned enough to remove salt build up. again good luck and hope i helped provide some information as im the type who likes to make others understand why something is doing what its doing, ive always been questionable of things and wanting to know why it works or how it works. wish there was more data available on how car wax works and such.
