I just ordered mine in the mail (M-sport moldings) and will have them installed in about a week at the body shop. There is double sided tape and then every 8-10" or so, there are little studs/locators that insert into the actual door panel. The factory BMW paintable pieces are primered gray, don't stand as far away from the door (not as tall) as the black ones, and are not textured but rather smooth.

I'll be posting pictures of my install when I get it done. Feel free to shoot me a PM if you need the part numbers from Tischer BMW. My local dealership wanted $400 for the 4 pieces, and I bought them from Tischer for around $200 shipped.