[Perfectlap]

winterminute,
what you should keep in mind is that the paint on your Boxser is VERY different to the paint used on GM and Chevy cars. Actually you can't buy the type of paint used at the Porsche factory here in America. If your car is ever in a collision you will be getting the American Porsche paint version which is much harder and less susceptible to scratching and micro marring but also not as purty.

Thus, California Car dusters and any type of dry dusting really is not good for your car. And for your Audi friends it's REALLY a bad idea. Good luck getting swirls out of that paint. Hardest clear coat anywhere. You actually need a special PC polisher attachement just for audi finishes.

If you don't want the top to fade I would get a softop cover which are sold on ebay for $50 and protect your interior from fading. It will protect the top without touching the paint.
Car covers are fine in theory but most people I've known use them too frequently and don't wash or clean the car each time they use them. It's unavoidable paint damage. I'm very sure you will get less paint damage going naked and parking in the shade vs. the cover. Paints, even the German ones, today are remarkably resilient to UV and all the other damaging rays. Your trim and soft top different story. But that's where disciplined use of 303, 1z vinyl and rubber or even armor all will pay off.

Swirls can be removed with an orbital poilisher but that stuff is micros thin and you can only do it so many times before the clear coat finish is in danger of failing.
Replacing your soft top and shooting a new layer of clear coat are two ENTIRELY preventable expenses.

p.s.
you are very lucky to have a car wash port! cleaning the barrel of my wheels is going to be a PITA without lots o' water.