Head unit radio reception (Phase 3)

[powerandtorque]

when I inscrewed the base for the respray, there was only the aerial lead held on by a nut underneath.

The aerial itself and the aerial base are two separate parts, but the aerial tends to seize into the base after a few years and won't unscrew.

Not a problem if you replace the base and aerial as one, which as you say is just a single nut underneath.