General Motors will end production of six sedans by the end of 2019.North American customers want SUVs, crossovers, hatchbacks and trucks. Sedans have fallen out of favor.As GM adjusts to changing customer behavior, the company also is planning ahead for the future.The company announced massive layoffs and is closing five North American facilities as it transitions to self-driving, electric cars of the future.The soon-to-be closed plants mean GM will no longer make these cars:Buick LaCrosseJanuary: September sales: 13,409, down 14.2%The LaCrosse is a large car built by a brand that was a pioneer in small crossovers. Buick is still shifting heavily toward crossovers: Sales of the Encore and Enclave crossovers are both up this year. But Buick is struggling after turning itself around a few years ago.Cadillac CT6January: September sales: 7,270, down 10.6%The only surprise of the bunch is the CT6. The Cadillac is an unusual choice for GM to cut because it serves as the tech halo for the brand. It's still the only car that has GM's Super Cruise semi-autonomous driving technology, but it's also the least popular Cadillac.Cadillac XTSJanuary: September sales: 12,664, up 15.9%Most XTS cars are sold to limousine and taxi companies. GM recently updated the XTS' design to keep customers happy, helping drive sales higher. It's the only car GM is cutting that has performed better in the first nine months of 2018 than in the first nine months of 2017.Chevrolet CruzeJanuary: September sales: 109,662, down 26.5%The bestselling Chevy sedan, the Cruze is highly regarded among auto reviewers and enthusiasts. The Cruze was the Consumer Reports top pick for compact cars last year. It was beat out by the Toyota Corolla and a handful of other small cars this year, and sales have disappointed.Chevrolet ImpalaJanuary: September sales: 43,952, down 13.4%The recently redesigned Chevy Impala was the 2018 Consumer Reports top pick for large cars. But it's a large car in a market that seems to have forgotten that large cars exist. The Impala is among the worst-selling Chevrolets.Chevrolet VoltJanuary: September sales: 13,243, down 13.7%The Volt is a plug-in electric hybrid sedan lost in the excitement of all-electric cars. Chevy has been promoting the electric Bolt hatchback, though Bolt sales have fallen too.