hey folks, sorry to post about something which i can tell has been talked about so much, but i kind of need a particular issue answered to suit my particular question, which isn't necessarily being mentioned here on prior posts.

I got a 92 240(DL) and want to put an after-market stereo in it again, after the last one was stolen some years back. I took the car to get the original tapedeck placed in there after my Pioneer was expropriated, and the guy at the car stereo joint said that he couldn't do that, my "amp was missing." from what i recall him saying it seemed that they removed the amp from my car when they put in the Pioneer, because the Pioneer had its own amp of sorts. Sounded reasonable to me, though I still wanted a stereo.

Flash forward about five years and now I finally break down and want some music in the car; I get a cheap Sony stereo from a friend and take it to an auto stereo dealer so I can get some adapters for the wiring harness and get it rigged up. Guy takes one look at my wires dangling out of the dash and says "no way. can't be done. the amp is wired funny, you can't hook it up, will need to get new wire harness and rewire from the amp." he mentioned how not all the speakers would connect, and how the amp, which he couldn't see but knew was in there somehow just by looking at the wires in the dash cavity, was wired for the original Volvo tapedeck and wouldn't fit on this Sony CD player.
Obviously this doesn't make any sense to me because as I mentioned I already once had a CD player in the car, and the guy at another shop years ago told me that I was missing my stock amp. ????

Anyone have any idea what this means? Where the heck is the amp in case I want to look at it with my own eyes to see if it's truly there? and what should I do if there IS an amp and what should I do if there ISN'T an amp? Do I really need to order some expensive wire harness from the internet just to get my third stereo working in there? What's wrong with the current set of wires already there?

Thanks so much for reading and any advice you can give!