Well, my wife finally got our 03 OBW into the dealer to get the AC looked at. Turns out there was no refrigerant in the system; it was totally dry. They leak-tested it twice and there are no leaks evident. They can't figure out what happened to the refrigerant, and SOA doesn't want to cover it as a warranty item if there are no leaks (actually, they told the dealer our car was probably hit in the front, which it was not).
Any ideas how the refrigerant could have vanished into thin air?