Ford 2003 Mustang Workshop Manual page 10

The radio type codes are:
2 — Premium electronic AM/FM stereo with compact disc (CD) player and clock
9 — CDX6+, AM/FM stereo with 6-disc compact disc (CD) changer and MACH 460 subwoofer
sound system
Z — AM/FM stereo, dual media (MP3) with compact disc (CD) player
Axle Ratio Codes