Hey Phil,
I've actually been thinking of doing this as well - I've actually got enough fly buy points for a trip to LA, and the Missus reckons overseas is not on, so I thought, "what can I do for a day or two over there and be back in a week?"
Hire a Mustang and take it for a drive!
It was interesting to here about the close inspection on return, but only to be expected I guess.
Hope you had a blast!
Aaron.