Factual error: In the scene with Joy in her "penthouse suite" at Planet Hollywood, the view out the window has two errors: it shows the "Eiffel Tower" at Paris and, off in the distance, Mandalay Bay (the gold colored building with a white band at the top). This indicates the view is to the south, yet the "Paris" hotel/casino is north of Planet Hollywood, not south; and "THEhotel at Mandalay" is missing (it's a gold colored building to the immediately right of Mandalay Bay when looking south - I stay there often and it's a great place; it's visible at 15:46 to 15:49). (00:17:45)
Factual error: In the scene when everyone is in the white Hummer, the vehicle is moving north on the Las Vegas Strip; on the right is Bally's and the Flamingo, with Treasure Island straight ahead in the distance. Yet a few seconds later, when Joy asks the driver to let them out, they are in front of the fountains at Bellagio, which indicates that they are now travelling south on the Strip - yet we never see the Hummer change direction or turn around.
Answer: 1971 Plymouth Satellite hardtop. You can see the Satellite's blue/white/red flag emblem on the grill.
Bishop73