wobbly inside rearview mirror 97 E420
 

The inside mirror on my dad's 97 E420 is very loose and moves when driving over a bump. I did a search, but it seems like everyone else used epoxy or drilled into it to fix it. Does anyone know of another method of fixing it other than buying a whole new mirror?

I have the car for the week because he went away, and it is annoying the crap out of me! (I'll still drive it over the 300E though)

Thanks for your time.