The midsized Optima is the vehicle that's largely responsible for Kia's U.S. sales breakthrough, proving yet again how important captivating design is to selling cars. For 2016 it gets redesigned. But don't worry, Kia didn't mess with success. All week long I would find myself parked next to other Optimas and I would visually examine the design differences to see exactly what Kia changed here. This is far and away their best-selling vehicle and it’s obvious they didn’t want to tinker too much with their blue chip car. Making it look even less new, my tester arrived in this nondescript Platinum Graphite paint riding on little 16” wheels finished in an equally dull light gray.