nmauduit wrote:What about trackers without service, e.g. TK103B or the like ?
You can get this type of tracker from Amazoon for around ?30.
https://www.amazon.co.uk/s/ref=nb_sb_no ... TK103A%29+I'm not sure how you could certify such to an insurance company. Basically they have a GPS system to know where they are and the circuits of a mobile phone to inform you. They work in two modes, either send TXTs to it and then it TXTs back with Lat & Long or it can be set to use mobile broadband and then send packets to a known server on which you register the device and the server then has a website with a map display showing where the tracker is.
All control is done by TXTs to it.
It has some extras
1) it can work as a burglar alarm, sounding the horn etc
2) you can switch it to monitor mode in which you listen to a microphone in the car
3) you can instruct it to operate a relay; this you usually use to switch off the fuel pump to bring the car to a stop so as a safety precaution it only activates the next time the vehicle is traveling at less than 20mph. If you don't have an electric fuel pump you could of course just use this to switch the horn on continuous mode which would no doubt attract the police.
As far as i can tell the only difference between the TK103A and the TK103B is that the latter includes a key fob which you can use to enable/disable the alarm facility as you walk from and to the car.