1999 Montana (and other radio questions)
 

I recently got a Montana, she's 11 years old, but is in amazing condition. I replaced the radio backlight that was burned out, and that's the limits of what need repair at this point. Instead now I'm intrigued by the steering wheel radio controls...

It looks like the CD player, radio and steering wheel controls are all hooked together via a data-bus. I'm wondering is this the same j1850 VPW bus that goes throughout the rest of the car? I'd like to tap into the buttons (and the rest of the car, if this is the case.). Is there any documentation on the protocols for the radio?

Markings on the radio:
Delco Electronics
PN : 09361452
CNBZ
Ser Man X
Prod ID : 2001
89CNBZR283281618