Hi Chris
The GPS jammer resolution is not a simple issue and I am not sure we will find a total fix. We can fall back on tracking the unit via GSM cell info, but this is slower and this gets us to 200-500 metres, not spot on, but not bad. However we have done further tests and the best blocker unit we have tested is still very localised with a 3 metre radius blocking range.
Ok to block in most cars, but not so effective in caravans or large motor homes. The blocker still doesn't help the thief find the unit, so when it's slightly larger than a cigarette packet it becomes even more difficult. As soon as the blocker is turned off, we get a signal in less than 30 seconds. Again as this is a self fit unit everyone will put it somewhere different making it even harder to find. North Wales police informed us last week that they had seen a couple of manufacturer fitted units being removed by going straight through the vehicle skin, prior to moving the vehicle, so if they don't know where it is then all the better.
Will keep you updated as we progress
Guy