EDIT - Sorry, Thought you were talking of the Chrome Frames.
You can Polish the glass. Check out the Detailing Forums for a kit to do the job.
It can also be done professionally. Went to pick up a car on Thursday from Dave at Exhaust Plus in Salisbury. He has just had the rear window of his fastback polished. Looks very good. Maybe give him a ring to find out who did it.
Rocket.