Buick Regal is a performance-oriented mid-size sedan. And because it's Buick's performance-oriented mid-size sedan, it doesn't wear its performance on its shirt sleeve. The supercharged Regal GS can match Pontiac's nifty Grand Prix GTP stride for stride, sprinting from 0 to 60 mph in about 6.5 seconds. But you would never know it just by looking. The Pontiac is an extrovert on steroids: All exaggerated bulges and air dams, it's like a muscular body in tight T-shirt. Conservative Buick prefers what we might call the 007 doctrine: Pack a powerful punch and a 9mm Walther PPK in the pocket of your tuxedo.