My old boss had an absolute gem of a tracker system. hard wired into the vehicle. An expensive system but apparently the evidence it gathers can be used in court.
You can set several "safe" zones so whenever the vehicle enters or more importantly leaves the zone, the system will send a text to your phone.
It gathers all information such as speed, route plotted etc... One time I was in the bosses vehicle going to collect some parts, the boss was demonstrating it to a friend just as I re-entered the workshop... bit embarrasing when he looked me in the odd way after reading out what speed I was doing on the way back.
There can be flaws occasionally the singal it gives out becomes a bit more sporadic and once messaged the boss at stupid o-clock when one of the vehicles with the tracker fitted was apparently 100meters from its usual resting place, the GPS signal had some how drifted without the vehicle moving anywhere
Such system is a bit out the reach of the normal user though.
