If you are tailgating this implies a pick up.. You have the holes to mount things on top.. You can get a "Stick" (Length of the proper size lumber) and stick in there.. Mount something like the JACK antenna (only time I"d recommend it) on the top of the stick, use the directional one so you can aim it Make the stick as long as you can or....
Use and extendable painter's pole to mount the thing. again the pole should (Minus bottom grip) fit in the hole in the Pick up, and a wooden wedge to hold it, and you can rotate it as well.