Driving to work in the morning with my daughter having a casual discussion (the sound system was turned down, not off). Heard popping or crackling noise as I told my husband about previously. Noticed acrid smell of burning electrical, then rear passenger compartment filled with gray smoke.

We pulled over and turned the car off (busy freeway, just before our exit). Extremely lucky that we didn't crash trying to get to a safe spot to pullover.

Right rear door had smoke coming from the door latch and window seal. I was standing by waiting on flames... after 10 minutes, the smoke stopped. Flames never appeared. But the door panel by the speaker was very warm.

Turned off the audio system and cautiously drove E-250 to work. Called my husband and was fairly irate. He looked up some internet info and said that it was possibly the rear speaker likely shorted out... he came by my work and pulled the sound system fuses (#67 & #69) and additionally mentioned that it could be related to hot weather (75 degrees that day @ 7:30am).

We have no CPO extended warranty. I am torn as to having the dealer inspect all other speakers... can't believe there's no recall campaign on this potential safety issue. I now have no audio system or phone connectivity thru our car and am not happy. This seems a recall and with other instances, Mercedes should definitely do something.