That is a standard car radio antenna plug (AKA a "Motorola" plug) used on car radios since at least the 1960s and perhaps earlier.
OEM plug is soldered in one like this..
The one the OP pictured is a solderless replacement.
I would be amazed that anyone used that anywhere else other than right at the back of the radio. Unless they really needed to extend the wire length.. Can be a problem at times since they tend to get loose over time.. You can buy Motorola plug antenna cable extensions if needed..