replaced the head unit with the old sony from my Alfa, no better..
moved up the ariel to be more vertical, no better..
will try cleaning the ariel base now.. is it easy to get at/out?
IIRC I just unscrewed the aerial and then theres either a couple more screws in ther or you can just take it apart, not too sure as it was a while back. But its easy enough to do.