I realize this thread is getting stale, but I will offer some clarification.
1993 Trans Ams did not have Monsoon systems. Monsoon systems did not arrive in Firebirds until 1997. The RPO codes of UL0 and UN0 you listed are Chevrolet Monsoon audio RPO codes as far as I know. Pontiac Monsoon audio RPO codes began with the letter "W."
The 1993 factory amplifier is what Delco labeled an "Active Audio Module," RPO code UW2, and is located behind the passenger side sail panel. The amplifier has a mounting tab that clips to a slot in the body of the car.
Tony (ZumpTA), to my knowledge there is no such thing as a non-amplified 10-speaker setup in the 1993 cars. Look at your Service Parts Identification label in your glovebox. I bet there is a UW2 code listed. The sail panel speakers are 3.2 ohm factory "subwoofers" that only reproduce low-frequency sounds. The factory amplifier is an active low-pass crossover for the sail panel speakers only. All other speakers in the car are powered directly by the head unit. The tweeters both in the front and rear have high-pass passive crossovers.
I think that pretty much covers everything.
Good luck in locating a factory CD player. They're pretty tough to find, let alone one that works, but they are out there. They look great in the car.
