Need purchase advice MP3-enabled “system”

Hi Car Audio Friends I need an MP3-enabled “system” for my car so slowly but surely. (MB C-Class BJ 11/97) With system I mean either a CD/tape/nothing radio + MP3 changer or an MP3 radio with normal cd changer or no changer at all. I have a Bose sound system in it and am absolutely satisfied with it, maybe some more powerful subwoofer comes in, but then I register again Now I don’t know anything about car radios, car audio, Wech sler etc and hope that you can help me there further. Have already looked around, what there is all there… What I liked best was the SONY CDX MP70. I have heard many times, however, that Sony should be bad and some had problems, if they had a Bose system in an MB C class + Sony Radio! Can someone confirm this?! As far as I remember there were problems with the volume, since this at the output (?) is not adjustable ?! () There are also other great Models, such as Alpine or Kenwood… however, they are actually too colorful for my car interior – but here we look over it casually, because I want to know what such a radio should/should have/can do. I have read through the website of the manufacturers and came to the following conclusion: Kenwood has a better radio, Alpine is expensive () and Sony has a good sound reproduction… I would like to have your opinions about it now, true I put a lot of value on good radio reception, a “shuffle” (random playback) mod that is versatile (with some radios you can only have an MP3 folder with it) and of course good sound reproduction. In short: it has to be a very good radio. What can you tell me about MP3 changers, what does it look like with folder playback, CD text etc.