A rearview mirror assembly for a vehicle includes an electro-optic reflective element, a back plate, and an attaching element having first and second spring-loaded electrical connectors disposed thereat. The attaching element attaches at the back plate such that the first spring-loaded connector contacts and is biased into electrical contact with a first electrically conductive element at a fourth surface of a rear substrate and the second spring-loaded connector contacts and is biased into electrical contact with a second electrically conductive element at the fourth surface of the rear substrate. The first and second spring-loaded connectors are electrically connected to a connector disposed at the back plate and are configured to electrically connect to a connector of a wire harness of the rearview mirror assembly or of the vehicle to electrically connect the first and second spring-loaded connectors to an electrical power source.