Well.....that is exactly how most of the MB dealers work!!!
I was laughed at in my face when I went to the dealer to buy some additional parts and tried to get some (electrical) information after I explained that I had bought a complete 1996 C36AMG
interior with CLIMATE CONTROL to install in my 1993 Diesel
They said that the climate control would NEVER function properly.
Can you imagine the look on my face when I went to the dealer (to get something) and three sales persons came walking to my car and asked me whether this was the 1993 "classic" with the 1996 AMG mods they had heard about!!!
ymsin; maybe you can order the mirror at Fastlane as well...
believe me: ONE powered wire and ONE ground will make the mirror work.