A flat base plate sits atop a motor-vehicle panel and is formed with a mounting pin extending downward through the panel. A flat antenna circuit board sits on the base plate, and a connector cable extends upward through the pin and through the base plate and is connected to the circuit board. A one-piece mounting element is unitarily formed with an upper face and latch legs projecting upward from the upper face and having barb ends latchingly engageable with the circuit board to retain the circuit board on the upper face. It is further unitarily formed with a lower face and latch legs projecting downward from the lower face through the base plate and roof panel and having barb ends latchingly engageable with the roof panel to hold the circuit board and base plate down against the roof panel.