After 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. At first they drive a Pontiac Acadian, then Dean steals a Dodge Challenger. After Bobby's death, Dean drives a Buick Special Deluxe and then, when he's in 1944, a Plymouth Roadking. After making it back to 2012, Sam and Dean drive a Buick Riviera to Seattle.
The vehicle was bought over for filming from Vancouver Island.