Hi Mr Lark
This is also a link to the type many of us have - these below do work with 3G cards whilst most others are 2G TK102B (but may work). 2G cards are harder to find now.
3G GPS GSM TRACKER TK102C SMS GPRS REMOTE Car TRACKING DEVICE Pet N0T TK102B 2G | eBay
Realistically you need a wired power supply and a 'waterproof' box to hold the contents ( glanded to your battery/ permanently live fused suuply). I have found the mini USB power sockets best and not subject blowing due to power surges from trickle chargers like the 'hardwire kits' sold)
Universal Twin Dual Port 2 USB 12V In Car Socket Lighter Charger Adapter SatNav | eBay
Either purchase a 12v socket outlet or solder (carefully) to the pins on the adaptor.
Welcome to RibNet - a great place for help and advice,,,, as well as some good sport every now and then