Have you heard about gps fleet tracking? Every time I heard that before, I thought about fleets as like delivery vehicles. Hubby is doing something with technology like this, but it applies to rental cars as fleet vehicles, per se. Essentially, what he's working on would track rental cars so the rental company could tell if the vehicle was likely to have been in an accident. The way it could tell is by tracking the speed - if there's a sudden stop, they can predict if it was slamming on the brakes, or impact.