Taillight Wiring Kit A self-contained wiring system that bypasses your towed vehicle's lighting with a set of independent plugs and sockets mounted inside the taillights. Wiring is routed underneath the car, to a socket mounted to the grille or fascia. Since the towed vehicle’s electrical system is bypassed, this kit eliminates the concern of voiding the vehicle manufacturer’s warranty. Note: the towed vehicle’s taillights must have room for an extra socket and bulb inside the lens housing.