Dodge Caliber Roof Black Plastic shows water spots

[theamcguy]

I have a 2008 Dodge Caliber. It spends all of its time in the garage or under a cover. There is black plastic that runs up over the A pillar, over the roof and incorporates a spoiler over the hatch. No matter what I do or what product I use water spots bleed back through in an hour. I have used Meguiars, Poor Boys, and DP trim restorers and within the hour the water spots come back. Has anybody found a solution for the plastic used these cars?

 

[swanicyouth]

Pics?