A vehicular rearview mirror assembly includes an electro-optic reflective element and a back plate, with a spring-loaded electrical connector disposed in a passageway of the back plate. The spring-loaded electrical connector is spring-biased toward an extended state and compressible toward a compressed state. The reflective element has an electrically conductive element established at the rear surface and in electrical connection with a conductive coating of the reflective element. A circuit element is disposed at the back plate and has an electrically conductive trace electrically connected to control circuitry. With the back plate attached at the reflective element and with the circuit element attached at the back plate, the spring-loaded electrical connector is compressed toward the compressed state and electrically connects the electrically conductive trace at the circuit element and the electrically conductive element at the reflective element.