Thanks for your response.
I don't have the car with me so no photos.
The Suby radio has an unusual antenna plug, with 2 small pins on the lead, and earth on the outside similar to a co-ax idea but with 2 small pins and it is bigger altogether.
There is a short lead from the radio down to the side of the left of the trans tunnel hidden by the console where the 2 antenna leads come up, one is male so I used a short extension and plugged it in (it works) but the other cord is female instead.
I think you may be correct a front and rear antenna, so I thought I would make a 'splitter' with 2 male leads and one female, see what happens.
I need to remove the passenger seat and CD stacker so I'll check out the leads further down next week.