You should have no problems with Anglesea Car Radio, 23 - 27 Church Street, Shirley, Southampton Tel : 023 8077 9013. Contact : Peter Allen. He will do Tracker as well.
I've used Anglesea for many years and are just about the only people I would trust to work on my Boxster, apart from the Porsche dealer themselves. The installation in my car is very discreet, the laser detector up by the mirror and the GPS antenna hidden away. Send me a PM if you want to see the job on my car and we will fix up a meet as you are obviously local to me.

Unless you want to come on wtsnet's Dorset Rennteam Run on 19th June.