05 A4 Cabrio A-Pillar trim discoloration
 

I have an A4 3.0 Cabrio. I just purchased it used with 16K miles on it. I asked the dealer to take care of the "splotch-i-ness" on the chrome/metal A-pillar. It looked to me that it just needed buffed or polished. The day I picked the car up it was raining lightly and the area looked fine.
Today the sun is out & I looked at it & it is "splotchy" or "mottled" again. I wentto the auto parts store and got some metal polish and did the one side and it didn't seem to help. Is this a "normal" condition with the metal trim that is on the A-pillars and across the top of the windsheild on the Cabrio cars?
Thanks
Vince D