Now I am thoroughly confused. The link seemed to show putting a 94 up radio into a 92-93 Bonne. I have a '90 and the steering wheel controls are quite different from the one with the airbag - they include buttons for the climate control temp, mode, and fan as well as the radio. Also the layout for the 90-91 is different from the 88 (not certain about 89).
Plugging the part number 16170212 into Google got several hits including
for $240 which identifies the radio as a 94 Grand Am but no mention of steering wheel controls. They also have the stock 90 Cassette radio which they say is for 90-92 with steering wheel controls
for $135. Such a deal.
I manipulated the image of the photo from e-Bay and the lower plug has five pins a space, then one more pin in it, a lot more than the connector.