Tried two different Sony headunits in there now. First one was OK but
not great, second one was atrocious.... Werid.

Get whistling noise on AM frequencies....

Electric aerial on car is shot anyway (Stuck) so I was thinking of
getting a replacement anyway. Will this help? If so, any suggestion or
are all aerials pretty much created equal?

Try a new aerial and a signal booster

Debbie.