Bailed out and buffed up, GM emerged from bankruptcy with a $20 billion public offering in November, the largest IPO in U.S. history. Early results look good: The automaker posted its first annual profit in six years.Daniel Akerson, GM’s fourth CEO since the government’s $50 billion rescue three years ago, plans to focus on four major brands — Chevrolet, Cadillac, Buick, and GMC. The goal is to cut inventory, close plants and dealerships, and otherwise improve efficiency. One sign of success: Its latest model, the Chevy Volt plug-in hybrid, was named Motor Trend’s Car of the Year. —P.N.