Originally Posted by nrr

Avistar, Smarkpark and Longterm (not the PA on site lot), provide valet parking--they park your car upon arrival and shuttle pax to the various terminals; on return, you call them and they shuttle you back. So, you must leave the key with them. I haven't used Avistar in a while, and never used LT, but Smartpark, photographs your car--this (presumably) will document any damage they caused.
With the "real" Longterm lot (owned by PA), you lock and park your car (and hence keep the key)--however, even though they have patrols, anyone would have access to your car once they are on the LT parking lot property. [Of course, if you leave your car home and take taxis, your car would be safe from damage at JFK.