Like many of you I remember all of those systems. I still have an underdash 8 track deck and speakers. I had thought about setting it into the coupe. We'll see, I've still got crates full of 8 tracks! I think I have 2 cassette decks.. and boxes of tapes too.
Reverb was a blast. We'd stack 2 or 3 together and try to "overdrive the sound".. Don't remember it working to good! LOL..

Coupe doesn't have any system in it now.. not sure if I'll put anything in. In the new cars I use the memory sticks, couple thousand songs is all I need I guess.. I've been listening to the same setup for 3 years now! LOL.