Used to have Cab Over Campers that we used on out pick-up trucks,,, I installed a radio antenna on the passengers side near the front,,, when we had the Camper on the truck the antenna clipped to the truck antenna with a alligator clip,,, worked great,,,
I am guessing they no longer make those ??? So we very seldom ever turn the radio on,,, because the reception is so poor,,, even after the factory replace the original one !!! All they had to do when they built the Sunseeker was hook the dash mounted radio to the antenna on the roof !!! DAU !!!