Thanks guys.
Two reasons for wanting a tracker, firstly because my insurers insist on it, already bought the insurance before realising the extent of the cost of a tracker Doh Doh Doh! But you live and learn.
Secondly, because it's another thing to add to my list of security devices.
The main thing is to be covered by my insurance should a thieving turd steal it.
In the end I decided to go for a smart track protector +. Seems cheap enough, and my insurers support it.
Cheers again
James