From website Mainstreet.com, April 2015:
"Fact: most rental cars are equipped with navigation and GPS systems. Are they used against drivers? Well, yes and no. The yes part is that, starting around a dozen years ago, newspapers were filled with sad stories of rental car customers “fined” hundreds - sometimes thousands - of dollars for violating the terms of their contracts. How? In one celebrated case, Acme Rent-a-Car of New Haven fined a particular customer $450 ($150 per incident) for exceeding posted speed limits. The customer had not received traffic citations. And the customer sued. The judge ruled against Acme. He did not dispute the right to track. But he said there was insufficient “notification” to make the fines justified.
In another famous case a Payless customer expected a bill for $259.51. He was instead slapped with a bill for $3,405.05, which was reached by adding a $1 per mile to each of the 2,874 miles he had driven, because he had crossed the California state line into Nevada and, later, he drove into Arizona. That triggered the fines, because the contract prohibited leaving the state.
In many more cases, numerous Florida car rental companies are notorious for literally shutting off engines of cars that cross state lines. The cars may be restarted upon agreement to pay new fees.
Is this legal? Neil Abrams, a car rental consultant in Purchase, N.Y., said, “It is legal as long as it disclosed.” As the Acme case illustrated, however, disclosure has to be loud and in a renter’s face. Fine print footnotes buried in a multi page contract may not be good enough for many courts.
What’s more, Abrams said that from his seat, use of tracking was much more prevalent a few years ago, perhaps because companies were exploring the limits of new technologies. “It was more true a few years ago," said Abrams. "There was a spotlight on it. It’s much less frequent now.” As customer anger grew - and negative newspaper stories multiplied - the big, national companies cut way back on use of tracking tools.
Case in point: Enterprise Rent-a-Car, in response to a reporter's question, issued a flat denial: “We do not install cameras in our vehicles. Enterprise Rent-A-Car, National Car Rental and Alamo Rent A Car passenger vehicles come equipped with only standard technology, as provided by automobile manufacturers. For example, some of our GM vehicles are equipped with OnStar technology – however, we can’t access the technology without an official police report (to document that a vehicle is lost or missing).”
Other big players have similar policies.
But driver tracking still happens at small, independent companies, Abrams said."
My old van may not be but your car rental could be...