Removed a faulty mirror following the excellent instructions but, I can't get the mirror to lock back in place. Took it to a windshield shop and they were unwilling to risk buying me a new windshield if they screwed up. I have cardboard wedging in in now but, that is not a solution. I was thinking about some WD-40 on it. Any suggestions?

 

I used white lithium grease when I re-installed mine - slid straight on and locked into place.

 

I'll give it a try.