The designers who have customized the Flex include Michigan based Mobsteel, 3dCarbon, Catalyst Industrial Marking, Kal Koncepts, Air Syndicate Inc (who created a custom Flex in conjunction with Kal Koncepts), Galpin Auto Sports, Automobile Magazine, CGS Motorsports, Rick Bottom Designs, Hot Rod Magazine, Heavy Hitters Magazine and Motor Trend.

Ford Flex by Mobsteel
Ernie Bunnell, owner of 3dCarbon, had something totally different in mind for his show car. His Flex reflects more European styling, with "a 10-piece body kit that makes the vehicle look sleek," he said. "To complete the look, we added 24-inch rims, a carbon fiber roof and a Katzkin leather interior."

Ford Flex by Catalyst
Motor Trend's take on the Flex was a little different from the other customizations, who concentrated on mainly aesthetic modifications. Motor Trend took a different route, with inspiration from the world of private jets for their Flex. While the Flex can usually seat seven passengers, inside the Motor Trend Flex there is a functional pilot's cockpit for the chauffeur and a luxurious private cabin for two, trimmed in leather and equipped with an information and entertainment system, bar, and humidor.