Bob Lutz, former CEO of General Motors, went on record recently saying that when they asked the government for money, they were told they had too many brands. This is why Pontiac got the axe; Buick only survived because of their success in China (I forget why GMC was spared).
But let's suppose instead of telling them they could have the bailout money if they lost some weight, they were told the company was too big and had to be broken up like Ma Bell was? Which brands would exist under each company? How likely would each be to survive?
My take:
Chevrolet Motors: Consists of Chevrolet, Pontiac, and Cadillac. Chevrolet is the main brand with Pontiac being a youth oriented budget performance brand and Cadillac being the luxury brand it's always been (think Toyota/Scion/Lexus for an OTL equivalent). GMC dissolved, but the Denali sub-brand continues as a high end trim for Chevrolet trucks (i.e. Sierra Denali becomes Silverado Denali, Yukon Denali becomes Tahoe Denali, etc).
Chances of success: High - these have always been GM's best selling brands. The only possible hitch is the loss of GMC since the two generally attract a different customer base - and neither one wants anything to do with the other (even given the fact that the only major difference between the two is sheet metal and interior appointments).
Opel Group: GM's European subsidiary becomes its own company. Buick continues under their wing and becomes a badge job company for North America and China a la Vauxhall is in the UK ITTL.
Chances of success: Medium/high - Opel does fairly well in continental Europe, as does Vauxhall. Buick is so closely aligned with Opel nowdays that this part may as well have actually happened. The question would be if Opel's management could keep the company alive without Detroit's guidance/money.
Holden: GM's Australian subsidiary goes back to being an independent company like it was in 1932.
Chances of success: Medium/low - from what I understand, most of Holden's products have been badge jobs of Chevrolet, Opel, and Isuzu products with the exception of a few standouts like the Commodore and Torana. Also, ITTL Holden's small market share in the extremely fractured Australian automotive market (they have over 70 brands on sale there) has made it unsustainable to manufacture there, so after next year all of their products will be badge jobs. Now, they could leverage some extra volume in North America and the UK by continuing to sell the Commodore in those places under its own name instead of the Pontiac G8 (in NA) and Vauxhall VXR8 Bathurst, (in the UK). They could also bring back the GTO/Monaro, as well as revive the stillborn Holden Ute/Pontiac G8 ST project by just building the chicken tax into the price. Maybe they could even make a new Torana based off the 2004 concept (if that'd been built - and made it to these shores somehow - that would've been sweet)...
Anyone else want to weigh in on this?