Im adding a Cat1 alarm with optional tilt sensor and also a fuel stop solenoid close to the tank which will be wired into the alarm immobiliser circuit plus I'm thinking a hidden switch also on this for extra security.
Fuel stop valve,

Anyway,
I've also been looking at gps trackers and wondered if they are any good and if they actually work, they range from cheap to expensive.
Anyone any experiences of them?
I'm looking at something along the lines of this,
http://www.ebay.co.uk/itm/GPS-Car-Track ... 19d9b43c73

I'm going to put a main battery isolator in also for security and safety,
Anyone have any other idea's, hints, tips etc that work?