Sometimes the car is featured in the film and there is sufficient demand from the public to encourage the manufacturer to continue the celluloid experience with a special edition.
Other times, the car has no relevance to the movie and is just created for curious marketing purposes.
The 2015 Kia Sorento X-Car is just such a vehicle.
Built to promote the DVD and Blu-ray release of X-Men: Days of Future Past, and the fact Kia is sponsoring the 2015 Australian Open tennis championship, the 'Wolverine' Sorento is (perhaps thankfully) a one off.
The mutant Kia features a custom bodykit with stylised adamantium claws on the front and rear, custom wheels and X-style decals.
The Sorento X-Car will be on display outside Rod Laver Arena during the Grand Slam tennis tournament in January 2015. We had a good look at the 2015 Sorento at the 2014 Paris motor show, but the Australian Open promotion will mark one of the first local appearances of the seven-seat SUV before its official launch in March.
What's more, the Kia SUV and tennis ace Rafael Nadal will team up with the X-Men to battle the movie's Sentinal robots in a series of online videos and wonderfully awful marketing collateral.
Concerned? You should be, as Magneto says, "mankind has always feared what it doesn't understand".