After trying super glue and epoxy, nothing seems to work on securing the plastic silver triangle that goes on the interior over the passenger side exterior mirror. :confused: If someone has any suggestions to this problem, please feel free to post.

Maybe a tiny dab of silicon caulk or head gasket goo might work. I used some to re-glue the shifter surround back onto the wood of my center console, and it has worked out well, so far.

A couple ideas
 

Make sure that all of the old glue is off the surfaces first. Try using 3M Adhesive Remover if it's not. I've used 3M Emblem and Trim Adhesive several times to reglue interior wood onto my dash.

Isn't it held on by a teeny tiny little screw?

There is no screw holdingthe triangle piece you are talking about. It snaps on with two plastic pins. These pins get broken off. I clean both surfaces and use silicon sealant. Use masking tape to hold in place for overnite. Simple. Try it.It will work.
Bill Lewallen Lexington,Ky.

I wonder why mine has a screw? Are you talking about the chrome triangular piece on the inside of the front windows that is the inside part of the outside mirrors? I do not have the right outside mirror but I still have the triangular solid piece on the inside. Both my mirror side and my passenger side triangle pieces have a screw. Factory screw too. I guess the 240D is different than the W116.

Patsy,
You are probably right about the triangle piece on the 116 being held on by a tiny screw. The car we are talking about is a 1981 240D which is the 123 chassis. I just checked the two 300s(123) I own and neither uses a screw. They use the plastics pins. Both have had the pins broken and have been repaired with silicon sealer. So far they are still in place. I enjoy reading your posts. Keep it up.
Bill Lewallen Lexington,Ky.

Bill and William,
Just another reason to own a W116 300SD. Everything is screwed down!

Patsy and Bill,
My wife drives a 1983 300SD(126)and if I can catch her out of it long enough, I will check to see how the triangle piece is held on. I have never had to stick it back on, so maybe it is held on by a screw. This is a very difficult problem, but don't despair. We will solve it.
Bill Lewallen Lexington,Ky.

YUP
 

Triangles and a little screw.....hmmmm
I wonder what Freud would have opined?
Ok, ok, my 300D has the snap on type,
and that ain't no ratchet!
:)