Mercedes-Benz is bucking the trend of increased automation and getting rid of robots. Instead, the car company is going back to using more humans when assembling its customized luxury vehicles, citing the fact that automated labor couldn’t keep up with the many options customers have when designing their cars.

With customers choosing design features from tires to cupholders, the robots making Mercedes’ S-Class Sedan just couldn’t make the cars fast enough, reported Bloomberg.

“Robots can’t deal with the degree of individualization and the many variants that we have today,” Markus Schaefer, the head of production at the automaker, said. “We’re saving money and safeguarding our future by employing more people.”

Bloomberg notes that Mercedes, along with other luxury car makers, are actually looking to add even more customization to their cars in the coming years—meaning that human labor could become even more important.