Thinking of putting a tracker on my STI to bring down the insurance so needs to be approved any ideas which is most cost effective,ie is there a subscription fee? aswell as a cost for tracker? and do different ones bring the price down more than others?

 

As far as i know, it doesn't affect the premium by enough to warrant the cost of fitting one in my experience. I own a MY03 WRX and had to get a tracker just to get insured. I have a Tracker Horizon on my car, and they are bloody expensive at around the 600 quid mark, then it costs me the lovely sum of 99 quid a year as well.
Robbery basically. But depends if you are tied to having one or not.
Gap insurance is a good bet to be honest. Cheaper by far. This site explains it all if you dont know what Gap insurance is:
http://www.autoinsuranceindepth.com/gap-insurance.html
But i wouldnt just buy a tracker thinking you will get loads off insurance, cus you wont. The discount will no way near cover the costs of and running of a tracker.