[cruisergeo]

obwan,
If you are talking about spots that will not come off when you use any kind of cleaner.
I had a real problem with mine last year.
I was even thinking about replacing them, until I bought some Maguires Gold wax.
I hand washed the car and was waxing trying to not wax the columns because I was afraid to put wax on top of these horrible looking spots.
I accidently dripped some Maguires Gold on the black spotted finish and when I wiped it off it was totally spotfree.
I mean it was completely clean. I used it on the columns and the problem was eleminated. Not to return again.
It has been about 9 months now and when I wax her down I make sure to include the columns and it shines like I always thought it should.
Give it a try.

[?]still waxin'