We used magnetic mount antennas for our hand held CBs purchased JUST FOR the trip out of Alaska to our home in Wyoming so we could stay in better touch driving two cars than the weaker two-way radios. On my truck (with a pop-up camper) I placed it just forward of the camper, centered on the cab roof. It angled forward slightly and probably bent backward a little underway. We had excellent signal for our communications. I never tried to raise others from a distance. If your friend uses magnetic and extra cable he can always stop and place it on the camper (higher) for an emergency contact.