To answer my original question (and provide an update): JFK is fully PC, and when I was there at around 9PM last night (12/12), stocked fairly well compared to some locations I've been to.
Off the top of my head, there was at least one Q60, a smattering of the normal Asian full-size sedans, a few SUVs (both domestic and imports), and two Range Rovers in the UG section.
I walked away with a nearly-brand-new 2018 Nissan Pathfinder (SV, with 4WD), the person checking me out said that they'd gotten a lot of new cars in recently. If I had been solo, I'd have gladly taken the Q60.