LAS VEGAS– Today CarMax, Inc. (NYSE: KMX), the nation’s largest retailer of used cars, and Dunkin’, America’s favorite all-day, everyday stop for coffee and baked goods, are inviting people to “do donuts” during their 24-Hour Test Drive — the delicious kind with frosting and sprinkles. Starting today through May 16, CarMax customers who participate in the 24-Hour Test Drive … [Read more...] about CarMax and Dunkin’ are “Doin’ Donuts” for New 24-Hour Test Drive Experience