Decided to take off the door cards today to find out a few things:
1. Why does my door rattle like crazy when I turn up the stereo?
2. How does the trim around the door handle come off?
My answer to Q1 was fairly obvious, and incredibly puzzling at the same time. In the photo below, you can see a white plastic box on the door card that is attached at 2 points with a plastic weld. This piece appears to be useless, but I still felt like it must be doing something so I should leave it in. However, it wasn't fixed tightly to the door card, so I used a piece of foam to tighten up the gap and eliminate the vibration. So far, so good. With the stereo up to 28, there is no noticeable rattle or vibration anymore.
Q2. The short answer is that there is no way to separate the painted door handle trim from the rest of the door card because it is plastic-welded together in several spots, as well as being screwed in a few places. From what I saw, there would be no way to just remove the screws, cut the welds, and reinstall the trim without having it rattle around. In order to paint these trim pieces I think I'll end up removing the door cards, taping off the trim pieces, and spraying them in place. I'm worried that it may not be a clean finish, but I think that as long as I carefully mask it off it should work out.