I broke the driver-side mirror as I backed out of the garage. The mirror is shattered and it looks like I cracked the plastic bezel surround, and maybe broke some of the inards that hold the mirror to the motor pivots.

Can anyone suggest where I might find this part?

Please see ebay @ Item #2409697044. The wiring may be different but you can work it out rather easily. These mirrors are painted also.
Good luck

Here are some ebay auctions for this item.
Drivers side mirror - $25
Used power mirror kit - $60
Manual operated mirror - $21.99
Salvage yard would be your next stop if you don't like any of these.
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1988 760Tic - 155,200 1966 M-B 230 sedan - 98,000 - Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.

I'd start with ebay, and then check out a salvage yard. You don't even want to know what that part goes for at the dealer. (I'm not sure myself, but I can tell you that the mirror GLASS alone for my 940 was $120. I opted to have it repaired instead at the local glass place.)

Also, check the FAQ for "Parts Sources". There's a good listing there of new and used retailers.

Good Luck,

Jeff Pierce
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'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)