Permatex, 3M and Pilot Automotive all manufacture high-quality car mirror adhesives. Car mirror adhesives are specifically formulated to be strong enough to glue side mirror glass.
A car mirror adhesive kit typically contains a cleaning agent, an activator and the adhesive. The cleaning agent removes old adhesive residue that may still be clinging to the surface. The activator and the adhesive work together to form a bonding agent strong enough to keep the mirror in place. The activator, which typically includes methacrylate ester, is applied to one of the surfaces to be glued, and the adhesive is applied to the other. The adhesive needs five to 15 minutes to cure and longer in colder temperatures.