…is this?!

Whilst I was in checking my auxilliary battery (which was sitting at 4.8v by the way 🙄 and not getting charged), I noticed two inline fuse holders. I then noticed this unit jammed into the bodywork next to the battery mount. The purple and green connectors go to a wedge shaped aerial tucked up near the n/s seat belt. There is nothing plugged into that multi-pin connector. It looks like a telephone unit but the car has bt phone anyway. Maybe some sort of tracker? No clues on it other than that yellow label.
So, anybody got any ideas? Oh and its coming out

Right, well it turns out its a Trafficmaster tracker.