The 2013 Buick Regal has a traditional name, but if you've wandered into a showroom looking for a V-8 and rear-wheel drive....well, things have changed. Today's Regal is a front-drive four-door. Sometimes it's a mild hybrid. It's never a V-8--it's never even a V-6. Under the skin, it's an Opel, from Germany. And it's the best Regal...