My 2004 E500 B4 radio it´s crazy, sounds only on the right side speakers, "failed connection" signs on the display ... anyway, the dealer says I need to replace the AGW (it´s in the left side of the trunk). Is there any way some local shop can fix the AGW? If not, is my only choice the MB dealers? They want a lot of $$$ for the spare ... shame on MB they are making profits with their own low quality products.