An antenna system is assembled to a dielectric medium on a vehicle and is spaced from an electrically conductive member so as to allow for enhanced antenna performance. The dielectric medium has first and second surfaces and a dielectric thickness between the first and second surfaces. An antenna is mounted to the first surface of the dielectric medium for receiving and/or transmitting signals. An electrically conductive member is mounted to the second surface of the dielectric medium for providing a floating ground that forms a capacitive coupling with the antenna. The electrically conductive member is dielectrically isolated from vehicle electrical ground.