Anyone have an FM modulated CD changer in there W126 with the 10 speaker Becker sound system? How do you like it? How was installation?

I have an 89 420SEL with the stock Becker 10speaker system. The sound is acceptable but I would like to add some sort of CD player (in-dash or changer) and I don’t want to spend a lot of money and I don’t want to have a portable one in the car with the cassette deck adapter.

The Becker in-dash player seems too expensive, ($600?!) and if I understand correctly adding a non-factory in-dash unit is a real PITA and can cost as much if not more than the Becker unit once all is said & done when keeping factory speakers. So now FM modulated changers are looking good to me, but I’ve never heard of such a thing until recently and know very little about them.

Any info and experience would be greatly appreciated.

Thanks
Clay