Don't know about the 8.5' wide, but mine works just fine for an 8' wide. K Source.
Apparently K Source only lists Sequoia and Tundra. Does yours look like this?
Here is the Land Cruiser mirror. Can't tell if it is the same as the Tundra. Might not be.
One of these might work if you can't find a custom fit like the K Source clip on. They get good reviews. They clamp to the bottom or top of the mirror case. A stiff case would be needed for these to work well.
http://www.dyersonline.com/dometic-grand-aero3-towing-mirror-set.html
http://www.dyersonline.com/dometic-aero3-towning-mirror-set.html
