I posted in the audio section, but have not had a reply. Here is the situation, I have a 1995 E320 with original stereo (tape deck no CD) and I am having the following problems:

-No sound coming from rear speakers
-Distorted sound coming from front speakers
-Antenna fell off car last week

The speaker problems have been on going for a long time, but the distortion in the front is getting worse. Does this sound like the head unit is failing or the amp? Would anyone recommend I replace with used same parts, or upgrade? Not sure how difficult putting a new head unit is in one of these cars.

Thanks