Demonology - S4-E17
Other mistake: Prentiss pulls up to a bar and the shot shows her looking out of the car window. "BAR" is shown reflected in red on the car window, but it is readable from left to right under the closeup of Prentiss's face when we see her. The reflection of "BAR" should have been backwards since it's a reflection of the sign on the building.
Chosen answer: Black SUVs are common police, military and dignitary vehicles around the world. It is not too much to assume they could be rented or owned by the police forces in the areas.
kristenlouise3
Other people have explained it but fore more information, federal cars would most likely be brought to the airport from the nearest agency, so they can drive out to their locations especially in rural situations.