involve the front end or side, rear parts are sometimes available from the wrecking yards. And since AS is the most popular color...you have a chance of picking up one from that source. Besides that, there are places that specialize in repairing bumpers...since everyone went away from steel bumpers there is a lot of business for them. Check with the local high end cars body shop.
http://mike.focke.googlepages.com/listsofsources