Buckingham is a vehicle manufacturer that can be found in GTA 6.
The company made its first-ever appearance in GTA 5, returning in GTA Online before being confirmed for GTA 6 in Trailer 1.
In the game’s first trailer, a 
Buckingham has previously been shown to have a defense contract with the United States government, for which it manufactures fighter jets and attack helicopters - though none have been revealed for GTA 6 at this point in time.
Interestingly, among the company’s large roster of planes and helicopters, Buckingham also manufactured a single tugboat, the Tug, in GTA Online.
It also potentially has a number of automobiles that are yet to be revealed, given that the Buckingham logo appears alongside other vehicle brands in the window of a Los Santos Luxury Autos dealership.
