Squirt I think you miss the point here, Scott as the owner has a right to know what his employee's are doing on company time, more so if he allows them to take a vehicle home.
You would be surprised at how many businesses use devices to track employees time running, stopping, speeding, idling and how many miles they drive daily.
It is perfectly legal to record all that, it is not spying, there is a difference and I do believe he has to inform the employee it is there, not sure but I think he does.
Say an employee refuses to drive a vehicle with that in it, what would the first thing that comes to your mind be, probably that he is doing things he should not be with the vehicle, right?
Scott is totally responsible for all that happens with his vehicles, if the guy goes shopping or to the races or hunting with it and Scott has not given him permission Scott still gets the law suit that follows, it is up to him to show signed papers saying the truck is not to be used for personal purposes. That tracking device is called a TOOL for the owner to be sure he gets what he pays for, namely an employee that is honest and does a full days work for a full days pay or is it night in this case.
Scott if all employees are required to return to the yard when done working I assume you have a time clock or some way to monitor that when your not there?
Jon