Hmm...I didn't realize there was a third audio option (with no amp.) I took a look at the WDS - there is in fact a diagram for a RAD2 radio as well as CCC with outputs going directly to speakers (connector x13812.) It seems it should work for audio purposes! (unless those outputs are turned off via coding, but I don't see why they would be.)
Its gonna be a few days (likely more) until I'm screwing around with my dash again - I'll let you know if there is audio out through that connector.