A wealthy and eccentric Dutchman, de Beaufort occasionally liked to drive barefoot and wore a Beatles wig instead of a helmet. He was too big a man to fit into contemporary racing cars, and competed in an old Porsche 718 as a private entrant.
In practice for the 1964 German Grand Prix at the Nürburgring, de Beaufort's Porsche left the track at the Bergwerk corner. He was thrown from the car, and suffered massive head injuries, from which he died three days later.