replace head unit for 1981 300SD
 

Don't want to spend a lot of money, but I really just need to know what's compatible and if I will need an adapter/wiring harness to work with existing wiring?

I believe it's a Becker Europa? All I can see is Europa Cassette, so I don't know if it's a Becker or not. Kinda sounds like a Blaupunkt, dunno.

Only requirements is that it would be compatible and have a single disc CD and be inexpensive (not cheap!).

Thanks.