The amount of testing that goes into vehicle design is, to put it mildly, obsessive. Exterior designs are refined to reduce drag by one more hundredth of a percent; Used Engine are tuned to eke out an additional pound-foot of torque; and cupholders are put through aggressive testing at rollercoaster-level g-forces over millions of miles of road testing.
Wait, what? Yes, even cupholder designs require extremely comprehensive testing, as you can see in the below video from Ford Europe. Dummy cups and bottles from around the world are tested to make sure they fit and remain stable in the cupholders. America's chief contribution is a giant soda cup, naturally. (And a shout-out to the bottle of Diet Vernors that presumably made it over to Europe from Ford HQ in Dearborn, Mich.)
The various containers are put through the ringer on the test track, undergoing acceleration testing, high-speed cornering at up to 5 Gs and a slalom course. To top it off, cupholder designs are put through "millions of kilometers" of real-world testing, as well.
Check out the video to see Ford's Used Engine ers hard at work ensuring your lap stays dry and your upholstery stainless.