The autodimming mirror should have it in the kit that comes with it. You can try contacting the company that makes the mirror, they may be able to sell it to you. Another option would be to go to home depot and look for wiremold in the electrical section. It comes in various lenghts and thickness and is cheap. You could cut it to length, spray paint it black and stick it to the glass with foam tape. It would probably cost less than $10.00 for the wiremold and the paint. Here's a link to the wiremold web site:
http://wiremold.com/www/consum...s.asp