My 1990 Civic sedan doesn't have a place to put in a mirror on the passenger side. The drivers side is a manual one. How can I put one on the passenger side? Any suggestion much appreciated.

does that plastic piece pop out? or from the inside?

Even after much struggle and some hesitant attempts at yanking it off, no it doesn't pop out. I have even taken the door panel out. Any clues? Thanks for replying