Although luxury coupes had been produced in North America for several decades previously, the beginning of the "personal luxury car" genre is generally considered to have started in 1958,[3] due to the success of the Ford Thunderbird (second generation) when it was redesigned from a two-seat car to a four-seat car.[4][5][6][7] These changes shifted the Thunderbird's emphasis from sporting to comfort and luxury, and sales increased by 50 percent.[3] The Thunderbird was sold for eleven generations up until the 2005 model year.