To get the mirror to work on the passenger door at about a 45' angle, you have to file the O in the plastic cup to a U.
You just need to undo the spring mounted screw, file the hole with a round file for less than a minute, and you can then get the correct angle.
To stop the mirror housing from drooping, insert a C washer between the D shaped metal plate and the mirror body. You need a very small C spring washer, about the size of those on the back of the clamp holding the Smiths instruments' clamps.
Once fitted correctly with these modifications, they work very well.