ashtray removal
Is your cigar lighter powered all of the time? In most newer MB's it's only powered in key position #1 or #2. If that's the case you'll lose all the radios settings such as stored stations every time you turn the car off. What's wrong with taking power from the car's wiring harness? The connector for radio will have two 12v conductors. One tied to the key position and a second constant 12v for the memory storage.
When you buy a radio from someone like crutchfield they supply a patch cord which connects the MB wiring harness radio connector to the back of the AL radio. You might want to contact them and see if they will sell you the correct cable. Then installation will be plug-and-play.
BTW, you are posting in a section of the site which is for questions about site use and not technical questions about your car. If you looked at the other posts you would see that almost all have gone unanswered. Mostly because no one comes down here.
The best location for posts such as this are in the Audio/Electronics forum or the W124 forum.
Good luck.



