For seasons 9, 10, and 12, Castiel used two vehicles: the 1978 Lincoln Continental Mark V and a 1987 Ford F-Series pickup truck. For Season 14, Castiel rotated through three different vehicles, with the Dodge Ram 1500 SRT-10 having been used the most often. That truck made one more appearance in Season 15 and Castiel was last seen driving a different pickup truck.
Throughout seasons 9 and 10, Castiel drove a jubilee gold '78 Lincoln Continental Mark V, which was also modified with hydraulics. Fandom took to calling it the "Pimpmobile" after Crowley sarcastically asked Castiel if he was a "pimp" for choosing the car. Castiel showed a fondness for this particular vehicle, telling Crowley he liked it and taking offense when Sam called it "crappy."
The car was stolen by Metatron in 10.18 Book of the Damned and later recovered by Castiel in 11.06 Our Little World, but the car was not used again after its final appearance in 11.10 The Devil in the Details. Castiel was possessed by Lucifer for months shortly after the car was last seen and apparently never bothered to recover the car afterwards.
Throughout season 12 Castiel drove a brown and tan 1987 Ford F-Series pickup truck. He acquired this truck after Lady Antonia Bevell banished him from the Men of Letters Bunker, sending him crashing into a field 3 hours outside Lebanon, Kansas. The original owner of the truck witnessed Castiel crash and emerge from the crater, and was then knocked out and his truck was stolen by Castiel.
The truck was abandoned at the lake house in North Cove, Washington, where Jack Kline was born after Castiel's death in 12.23 All Along the Watchtower. It made one more appearance in 14.18 Absence in a flashback scene set during season 12 where Castiel and Mary Winchester speak about her return after a vampire hunt.
2019 Ford Fiesta
Ford LTD Crown Victoria
In 14.15 Peace of Mind, Sam and Castiel drive a grey Ford LTD Crown Victoria when they are on a case in the small town of Charming Acres, Arkansas. Fandom came to refer to this vehicle as the "Bird Poop Car" due to the deliberately-placed bird poop running down the the back passenger window.
Dodge Ram 1500 SRT-10
For episodes 14.17 Game Night, 14.18 Absence, and 14.20 Moriah, Castiel used a silver Dodge Ram 1500 SRT-10 pickup truck to travel. When he goes off to Wyoming to fish in 15.06 Golden Time, the truck can be seen parked in the distance. In 15.15 Gimme Shelter, Castiel has apparently abandoned this truck in favor of a different pickup truck.