This is the original mirror that came with the car; after 11 years, it fell off the front windshield and was dangling by its electrical cord. I bought Permatex Window Adhesive, did everything according to the directions, attached the mirror - and after two very hot days it fell off again. I don't know if it was the adhesive, the weather or something that I did, but I'm going to try it again using the 3M Rearview Mirror Adhesive instead. And if all else fails, will go the dealership.

Update from Sep 16, 2021: I know what I did wrong, I read the directions incorrectly, I thought it said to coat both the button and the windshield with the wipe, but that was not right. What I was supposed to do was wipe the windshield only. Since I did not do that, the mirror fell off two days later. I think this is why this product has received a few negative reviews on other websites.

Update from Mar 8, 2022: Update, on rearview mirror installation: bought a tube of 3M Rearview Mirror Adhesive on-line, and it worked. One more point, Toyota dealership gave me quote between $50 and $60 to do this type of job. It does not take very long to glue it on, but preparation is critical; the button and windshield must be clean of all adhesive. In addition, temperature must be between 60 degrees Fahrenheit (ca. 16 °C) and 90 degrees Fahrenheit (ca. 32 °C) for installation. The instructions on the 3M Adhesive said that after gluing the button to the window, it takes about 15 minutes to fully cure. Well, I waited one day before reinstalling the mirror, just to be cautious. So, far so good.

Purchased used in 2014 and no problems for 2 years....great car!!......

Rear view mirror fell off, purchased Permatex repair kit for $5 and followed instructions to a "T"......mirror instantly fell off when I tried to reattach.

Purchased another kit....this time I let it dry for 24 hours instead of the 30 minute prescribed time. Reattached the mirror but it instantly fell off again.

This time I made an appointment at Riverhead Toyota.....2 1/2 hours and $40 later it was attached. After sitting in the driveway for 5 days, I decided to drive it to work......Fell off again.

Now here I am, a week later, went back to dealer, 1 1/2 hour wait, reattached, and was told not to touch the mirror for 2 days. However, the "technician" attached the button at an angle and was able to snap on one plastic cover. The second cover which conceals the wires was on the floor. He was unable to install it because the button was crooked. Now I have to take it back and have them pop the button off and properly reattach it.......unless it falls off on its own.

I spent two and a half hours in the Toyota service center waiting for them to re-attach the mirror, at a proposed cost of $60. I did not spend this because at the end of that time the service manager came to tell me that they had not been successful and that I would have to return the next day, at the same time, when the glue had had 24 hours to dry. The next day I noted that the small mounting device had been glued on crooked, so that the sleeve intended to cover the wires would not fit over them.

I did not return because I have a life beyond the maintenance of my Prius, much as I appreciate it in general.