Recently my brake light went on and when I inspected my brake fluid reservoir I discovered it was empty. After speaking with the Audi dealership it appears it could be something as simple as a bad seal, brake line to something as complex as a new master cylinder.

Has anyone had a similar experience or any insight into this matter?

Also I am looking for a good mechanic in the LA area.

My Audi is a 2000 A4 1.8T Quattro manual 45,000 miles