See a copy of my email to the local stealership below....
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Mr "X"
I am trying to investigate if my 2002 SLK32 has been wired to accept an auto dimming external side rear view mirror.
Is there any way you can tell from my VIN?
VIN = WDB1680322J338531

See Item 1&2 in attach….
http://www.parts.com/parts/2002/MERCEDES-BENZ/SLK32%20AMG/?siteid=2&vehicleid=1417081&diagram=5766385&diagra mCallOut=4

I’ve just replaced my interior mirror – fantastic! The auto dimming is brilliant.
I’m hoping I can buy a new RHand side auto dimming mirror glass and even though the car may not have originally come with a “heated” and/or “auto dimming” mirror, if I buy one it will simply plug in…
I’m also assuming it picks up its dim “command” form the interior one (if you can find out - ??).
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Now if anyone is cluey enough to scruitinise the electrical diagrams....it may very well tell the story....

b22b

 

I do know that the internal auto-dim mirror has NO outputs, and only uses 12v and ground to work. The forward and rear light sensors are in the mirror itself.

 

hmm...okay I guess I was assuming if the external auto dimming mirror had rear/front photo sensors they would be obvious, to which I havent heard.
...anyone see any pin holes in the front/rear of their external mirror that could be the sensors...?
If you cover the front one up with your finger - does it dim?

for those with auto dimming rear view mirrors and external mirrors - if you cover up the front sensor of the internal rear view mirror - does it turn green as well as the external mirror - or just the internal one...;>)

b22b

 

I have the breakdown with pictures and numbers from the Mercedes parts list, that's the full parts list not the body shop list.
The info came from this PDF.

 

bumpity bump