Hey, just got the DTM rear carbon fibre wing and I prepped it for install today.......(not too long)
 

You really need to wet sand with 600 grit sandpaper and go over it well. If the edges aren't painted black, make sure you do that as well. Then I clear coated the entire thing top and bottom with a medium reducing Urethane clear coat (painting at about 70 deg F). I applied 1 light coat then three progressively heavier coats. No need to buff out afterwards, unless you are very very picky. To support it, I drilled two 1/8" holes underneath at the end of each base where it would mate with the window and then supported it with basically pegs up off of the floor. The frame is aluminum so don't worry about drilling. That way I could coat both sides. I am using some 3M urethane adhesive used for sealing auto windshields (the nasty black stuff).

I'd post pictures, but I am poor...no digital camera. If you want, I could scan some 35mm shots in a couple of weeks.

Mike