Gurney's tall height, unusual for a race driver, caused constant problems during his career. During the 1.5-litre era of Formula 1, Gurney's head and shoulders extended high into the windstream compared to his shorter competitors, giving him (he felt) an aerodynamic disadvantage in the tiny, underpowered cars. At nearly 6'4", Gurney struggled to fit into the tight Ford GT40 cockpit, so master fabricator Phil Remington installed a roof bubble over the driver's seat to allow space for Gurney's helmet—now known as a "Gurney bubble". In a fortunate error, the Italian coachbuilder who built the body for the 1964 Le Mans class-winning, closed-cockpit Cobra Daytona GT coupe driven by Gurney and Bob Bondurant mistakenly made the cockpit "greenhouse" two inches too tall — the only thing that permitted Gurney to fit in the car comfortably.