Hey, which 1992 radio are you looking for?
I think the base 2 radios are the same as 91, with the base being a Double Din Tape Deck with the mid-grade being a Double Din Tape Deck with Equalizer. The top is a separate single din tape deck with an accompanying single din CD player. As far as I know, the two double din units are the same as the 91 cars, but the cd unit is different.
I've located some sources for some of them, so if you let me know what you are looking for I can provide you some links!