Federal law mandates that all vehicles manufactured today have a rearview mirror if the vehicle is equipped with a rear window. However, because the mirror is essentially glued onto the windshield it is somewhat common for the mirror to fall off. If this happens you need to either reinstall it or install a new rearview mirror. If you choose to drive the vehicle without one, you risk being fined if pulled over in a traffic stop and you risk failing a state vehicle inspection.
Scrape the old glue off the inside of the windshield with a small metal scraper or flat razor blade.
Wipe the windshield clean with an alcohol rub.
Coat the back of the rearview mirror button with rearview mirror adhesive. This adhesive is readily available at most auto part stores.
Press the button onto the windshield and hold it in place for one minute while the glue becomes tacky. Let go of the button but wait one hour before attaching the mirror to the button.
Place the base of the rearview mirror onto the windshield, directly above the button and then slide the mirror onto the button.
Tighten the set-screw located on the base of the mirror. This secures the mirror to the button. Usually, the set-screw requires an Allen wrench for tightening.
