Tracker required by insurance - probably the area I live in, so not fitting one out of question. I'll probably go for Tracker Horizon or Monitor, or Smartrack.
There is official Tracker website offering Monitor £361 and Locate(new model, used to be Tracker Horizon) at £462 plus subscription. At the same time there are other websites (like Trackerfit.co.uk) offering Monitor at £174 and Horizon for £235, incl. installation - way cheaper.

Does anyone knows if it's safe to get it installed by these independent installers and why they do it cheaper?