Mini ariel

Ok, so I was passing the local breakers & spotted a wee mini. Don't know what year it was, but it had its aerial. So popped in & got it. Two wires going in, one is antenna, the other is a spade connector & looks like maybe a 12v feed?? Anyway got in about mine & mine only has one cable, just a thin one that plugs in. Although the antenna itself (the one that's on it just now) has two wires, but one isn't plugged in. Also, the one that's on my car just now that I thought was an aftermarket shark fin, has mini on the label, so don't know if it is an original part. Any ideas.