This has been bubbling under the surface for years. I can't help but feel that misuse of IT fares is the next thing that airlines will get strict on.
Well, I say airlines, but I really mean 'BA', as other airlines get strict on it (i've seen a certain SE Asian airline getting ballistic over it

). Didn't realise that VS has already taken steps...
But at the moment, if you don't pick up the car (as opposed to cancel it) I have no idea how you could be taken to task for it. However, there are lots of advantages as people have said to having a car in Vegas. Could you not pick it up the following day from the airport? I also can't stand driving after a long haul. A bad experience at LAX put paid to that, closely followed by driving to Drakensburg from JNB after no sleep in Y.