I have an original 1972 Plymouth Scamp. When looking over the car I noticed an electrical terminal coming from the trunk area to the package tray. The terminal is attached to a chrome relay box which is mounted in the trunk and has coax cable running to the front of the interior under the carpet. The cable appears factory as it has fasteners keeping it in place. The end of the coax looks like the same male fitting one would use to connect to a CB radio. I first thought of a CB radio, but the end terminal is inside the car. Previous owner long gone, so no help there. Anyone have any ideas?

Probably some sort of antenna. Are there holes drilled under the dash that might have been used to hold a bracket for something? Might be for one of those old reverberator units. They were popular back then. If it looks like a factory install, it could have been a dealer add on option but I can't find any reference to one that would be close. Not in 72, but starting in 77 Chrysler offered an AM/FM/CB option for the trucks.

Back in the 70s, most aftermarket stuff was installed to look like it was factory oem. There was actually pride taken in a well done job, just another thing that has fallen by the wayside. Gene