Okay. It appears that the silver plastic is painted on. here are the best closeups i could manage, but if you look close (don't forget these are clickypics, and i think you can actually make them even bigger) the edges of my glovebox have slight worn spots where the silver has rubbed off and it seems to be woodgrain underneath.
it can also be scratched:
and for the radio pod:
it is an overlay, and does have reflective capabilities.. but i also believe it has a clear coating over it so as far as staining.. you may or may not be able to clean/polish it off without scratching. I would say your best bet would be to just cover it over with something similar.. i'm sure somewhere someone makes a sticker type thing that resembles brushed alum. It is about 1/16th thick. it can also be scratched up which is why i think it has a coating. you can also dent it, and break it (i have a small piece missing as you can see in the photo.. my fault for pulling on it for the pic)
hope this is helpful.
oh.. and you mentioned my door panels.. yes i did them myself with SEM. I did them up black where the blue was faded or browned. They look so much nicer. I also did up the armrests to match.