See if the radio has the keyfob programming option. My 2000 has programming related to: doorlocks, keyfob programming, chirps, lights, oil life reset and tire pressure monitor reset.Weird, huh? Do you happen to know if my car would support keyless entry? The guy I bought it from (third or fourth owner) said he never got key fobs.
Keyfob programming deletes all of the FOBS and then you add up to 4 back.
That should be your Antenna lead.The only reason I'm still leaning that direction is that I don't want to run a REM wire from my new deck to my new amp, but after I get this firewall plug removed to feed the 4-gauge, I might talk myself into doing exactly that.