Amy here...with a crazy story about my 16 year old sons car. (SPOILER ALERT: It has a happy ending!)
Backing out of the driveway with me in the passenger seat, Corben braked to put the car into drive. It is a gorgeous, unusually warm spring day and our windows are wide open. CLINK-CRASH, clatter-clatter clatter, something metallic hit the ground. We both looked at each other confused and speechless. (He later said that he had first thought it was a hubcap.)
We both turned to look towards the window and noticed his side view mirror was gone--not the whole fixture, just the GLASS mirror!
He opened his door expecting to see shattered shards all over the road but instead, there was the small mirror in perfect condition!
I ran into the house to grab a bottle of the Best Glue Ever and a scrap of foam rubber from which I cut off a scrap to use for a disposable "brush". I applied the Best glue Ever, in a thicker layer than typical for most crafting purposes.
It was set aside to let the glue dry until the white glue turned pretty nearly clear. At this point, it is VERY sticky, grabs well, and forms a very strong, waterproof bond.
I have complete confidence this will last "forever, as we did a similar repair about 5 years ago to my car. A small round mirror had been applied to side mirrors to aid in viewing when pulling a trailer. The original double-stick foam tape wasn't holding well enough and the mirror kept coming loose. I applied a layer of glue to the foam tape and let it "dry to clear" before pressing it back on the window. It has traveled through desert heat, mountain snows, occasional thunderstorms, and the winter drizzle that we are known for here in the Pacific Northwest... and that little mirror is still absolutely holding fast!