I would just get a different radio-

Those were suppose to have a battery- long since dead. Dealerships don't like those as they take a tool. You have to pull the radio to re-set it I believe and they can be nice and do it for free- or they will charge you.
Get a replacement Becker radio- with a code card and cd player. When they have refurbed units, they are about $250-300. BE 4604? They can even wire it up for IPOD input if you need it.

Michael