[QUOTE=Caractacus Pott]
I’m in northern Japan and it seems about a quarter of the cars on the road have one of those mirrors, though they’re mounted only on the driver’s fender. Oddly, they’re much smaller than the door mounted mirrors. I wonder if they’re convex mirrors? <snip>
[/QUOTE]
Following up, they’re convex on current vehicles, so no more of Rick’s adjustment method.
Can’t understand why they wouldn’t be powered for adjustment like any decent American car’s side view mirrors are. 
Quite possibly because the Mitsubishi pictured in the OP was built in the 1960s, and electric power mirrors pretty much did not exist then.