The old backside will tell you on South Korea’s bumpier roads that the Koup SX has a rather stiff suspension and firm, controlled damping, which means you’ll feel every washboard road rung and expansion strip. Like everybody else’s coupe these days, the Koup shares only one piece of sheetmetal, the hood, with its sedan sibling. It’s two inches shorter, 0.4-inches lower to the ground and about 45 pounds lighter.