Fixed my mirror by swapping some the guts of [MENTION=119029]NinjaOne[/MENTION] 's old mirror into mine (detailed, pic heavy, write-up in progress). In the process, found this in his behind the mirror motor and everything:
Not sure what kind of flying stinging pest this is for...
I found it fitting since I found a bunch of long expired tiny moth cocoons in mine when I took it apart. Maybe I'll rename my 4Runner to the Ark of Bugs or something, especially considering the storm we have approaching the PNW.
Write-up link will go here when done.