Dean: Nobody puts baby in a corner!
Sam: You know that's a line from...Dean: Swayze movie! Swayze always gets a pass!
When Leviathan!Sam and Leviathan!Dean go on a killing spree (while driving a '67 Impala) causing the real Sam and Dean to become America's 2nd most wanted criminals, Frank Devereaux advises the boys to lock up the Impala to avoid detection.
The first car they drive after storing the Impala is a four door hatchback Pontiac Acadian (possibly an '83 model) with Wyoming plates: 3 2E6. The Pontiac Acadian was a version of the Chevrolet Chevette sold in Canada from 1976 to 1987.
Hanging from the rearview mirror is a My Little Pony - similar too Rosedust Queen of the Flutter ponies - which Dean cuts down with a knife and throws in the back seat. It is later seen in the trunk along with the severed heads of the leviathans.