This is kind of a spin-off from a comment in the thread discussing the interest in Hummer by a couple companies from India:
What would it take for GM to merge some brands? Take the whole clustering of brands (Buick-Pontiac-GMC for example) to the next level, and have them share a corporate shell and legal entity. Let's call it "GM Specialties" for now. Some thoughts:
+ Dealerships would have a contract with "GM Specialties", not the specific brands contained within. A Specialties dealership (auto boutique?) could order (or not order) any product from the Specialties' included brands, maybe with some requirements/standards as to how the products are displayed and/or marketed. This is not terribly different from a department store. If, for example, California has very little demand for product A, but the midwest does, then maybe some Cali dealers will choose not to order, stock, or market product A. They could still be able to special order product A for those few people that "gotta have."
+ "Failed" brand-names could be phased out without severe legal repercussions. They could also be right-sized. Think Hummer taken down to only one model (probably a Wrangler competitor). When one brand-name shrinks because of market demand, Specialties management can recognize where the market is growing, and provide more product in that segment to even things out (SUVs get cut, new compacts introduced). The dealership may be a little frustrated at having to rework some showroom floor to adjust, but for the most part they're happy because their product is moving with the market.
+ Brand names never truly die. What's to say they couldn't bring back Olds as a couple special models? Drop Hummer for a little while, then bring it back? GM doesn't have the $$ to invest in a product worthy of a brand/segment? Wait a couple years, the dealer has other product to keep it afloat.
+ While in some respect, this idea is another way to homogenize GM, and in a management level kill some of the things that make brands special, it really empowers brands as well, allowing them to be what they are truely meant to. Pontiac is burdened with having to carry some plain-jane models and rebadges, because the dealers need product that'll sell. If there are other brands to support the same dealer in volume sales, then brands like Pontiac have more freedom to exist as fewer, more true performance vehicles.