Thanks very much guys, very helpful. I was attempting to unscrew the whip but like you said they're very corroded. I'm looking at getting a generic aerial off ebay for about £6 I think... something like this?
It's a bit tricky to get the the fitting. I took the light out and had a look but...
If you look closely it's actually snapped, I'm not sure how much of what I would need to replace hence I'm asking here. The aerial itself is intact it's the base that seems to be broken.
So my Nissan Micra has had its aerial snapped off, must've gone through a car wash with it still on or something, and I'm attempting to sort it out because the reception is terrible and sounds all fuzzy.
I'll attach some pictures of the aerial to demonstrate my problem. Any recommendations...