adding CD to my '83 300D

[JHZR2]

Hi,

I have an 83 300D with the original becker europa cassette player and pushbuton analog radio. Call me crazy, but I have gotten used to it over the digitals Ive owned, and would liek to keep it. I never use the cassette, but do use the radio. The thing is that I would like to add CD capability to the stereo. I was thinkign of trying a CD changer, perhaps trunk mounted. I would liek to know if anyone would think it possible to add this and maintain use of my old radio. I recall some old CD changers that either worked on radio frequency or somehow spliced into the antenna wire, because my friend had one that was like that, hed set the radio station and be able to play cds from the changer via a handheld remote.
The one thing I dont want to have is a portable CDplayer with a cassette adapter. I recall his raido operated one sounded quite good, almost as good asd my built in, but the cassette adapters sound lousy to me now that Ive heard all the types.

Any info is most appreciated.
Thanks

JMH