I switched the tuners/amps as OlBlueEyesBonne instructed, but my steering wheel buttons still do the crazy functions they always have.

JDB, just read your PM'*. I wonder if your 1992 radio might have been worked on in the past and had the amp/reciever portion replaced with a unit from a Buick (guessing 1994/95 -single DIN). Just talked to my brother about this and he said he'd never encountered that with this vintage radio, although that is how the steering wheel controls work in his 1998 Olds LSS -he installed a Buick Monsoon CD/CASS unit and the steering wheel controls have different pin-outs at the radio.
Check ebay -I believe I saw a 1992/1993 Pontiac AM/CASS/5-band EQ radio for something like $5 + shipping. Might be worth a try.
I'd try swapping a Buick amp/reciever onto a Pontiac radio, but without a Pontiac with steering wheel controls I can't test to confirm this.
Forgot to ask my brother when I was talking to him, but I'll see if he has a service manual for these radio'*. I know he does for some years, but I'm not aware of which ones he has.

The resistor trick works because it takes a brighter laser to read CDRW, as they are not black/relflective, but more dull/reflective.

hmm that'* interesting. But when i switched the tuners, i had to break the manufacturer'* sticker connecting each one to the faceplate which makes me think neither unit had been tampered with, unless the sticker was a repair sticker. What makes me doubt this would ever work is that the steering wheel button wire, light green, plugs into the auxillary plug on that back, not into the tuner itself. I traced this wire to the circuit board perpendicular to the faceplate, but i could not trace it any farther. I tried to swap that circuit board between the two radios but could not get the fader/balance ***** off.

Did the buick or grand am have a mute button instead of a power button on the wheel?

Bump. I'm still not convinced that the tuner is what interprets the steering wheel inputs.
I found a date on the INSIDE of my cassette tuner: 1-13-93

Edit: The verdict is in. The steering wheel inputs are NOT interpreted by the tuner portion of the radio. My buttons work properly with the 93 cassette and 93 tuner. They do not work properly with the 93 tuner in the 95 cd player.