becker cdr 220 radio code

[Chboro]

As someone else posted I prefer listening to the vehicle over the radio. Just to show how often I actually turn it on, it was 3 months ago the battery died and I had to replace it. I recently took a 2 hour trip and decided to try out the radio and CD player and that's when I realized I needed a code. Prior to the battery going dead it did work because I put some CD's in the remote changer and tried it out. Anyhow, I have the CDR-220 and I just tried what someone suggested to obtain the serial number and that didn't work at all. Unit powers up with PORSCHE displayed, then asks for code. I have the radio manual and obviously the code card is missing. It is a 2001 Boxster S. Any suggestions short of going to the dealer would be appreciated.