Cars accounted for just 30 percent of U.S. production in 2017, down from 38 percent in 2014, according to IHS Markit.
Car sales in U.S. on pace to hit 60-year low
Some automakers were better prepared than others for the shift from cars.
Subaru of America has been cashing in on the crossover craze to the point where it is on track for a 10th consecutive year of record U.S. sales in 2018.
Part of the once-niche automaker's success: Two of its most recognizable nameplates, the Outback and Forester, were pioneers in the crossover segment in the mid-1990s.
Through May, the brand's car lineup — the Impreza sedan and hatchback, Legacy, BRZ and WRX — has made up 24 percent of its U.S. sales, down from 58 percent in 2013, meaning Subaru is among the automakers with the biggest shift to light trucks.
At the same time, Subaru's total sales grew 53 percent from 2013 to 2017, even though its car volume has declined.
Crossovers have become such a huge part of its business that it sold more of them in January through May of this year than it did in all of 2013.
Despite that crossover growth, Subaru says it remains committed to sedans.
"We're not abandoning these segments, for sure," Subaru of America CEO Tom Doll told Automotive News in May. "We still sell some nice volume in that segment, but given the change in the market dynamics, moving from sedans into these smaller SUVs and midsize SUVs, it's a market trend."
Not every automaker has had the benefit of a crossover-laden lineup like Subaru's.
At Hyundai-Kia, 59 percent of its U.S. sales this year through May have been cars. While that's down from 78 percent five years ago, it's the highest percentage among the 15 largest automakers.
Hyundai-Kia's product plans call for a significant shift as it tries to play catch-up with rivals. Hyundai plans to introduce eight new or redesigned crossovers in the U.S. by 2020 to a lineup that has had redesigns and freshenings of its cars.
Luxury brands, historically known for their stylish sedans, also are filling dealer lots with more light trucks as quickly as possible.
BMW Group — the only sizable automaker besides Hyundai-Kia still selling more cars than trucks — and Daimler are adding numerous nameplates to their crossover and SUV lineups.
LMC's Schuster said luxury brands were late to the crossover craze "but are now coming in full force, with the Germans leading the way in fragmentation."
Michael Wayland contributed to this report.