Tracker & Anti-hijack devices

[sarg]

Chaps

I've almost bought the replacement for my A8 (not an Audi, sorry) and am looking into having a tracker and/or anti-hijack system fitted, but finding it very difficult to find much info on all the different choices.

So, can anyone advise on or recommend a system - I'm most interested in a tracker as it makes quite a difference to the insurance rates, but would also like to find one with a cheaper subscription cost as these are all a bit expensive.

Thanks in advance.