This has been the case for GM, which has discontinued its share of car brands over the years, including Pontiac. This move came after GM filed for Chapter 11 bankruptcy protection in 2009, which led to a massive restructuring plan. But not all GM brands shared Pontiac's fate. Four GM brands survived the cull: Buick, Chevrolet, Cadillac, and GMC. Buick, for its part, was one of GM's most profitable brands at the time, and this quartet became GM's focus moving forward.