So just which brands were profitable for GM?

i don’t know the answer to the question in the headline, but it popped into my head the other day as I was reading the various corporate obituaries following Rick Wagoner’s removal from GM.
One of them mentioned that GM have lost around $80billion dollars in the last four years.
That’s $80,000,000,000 and to put that in perspective, that’s more than 10% of Australia’s 2007 GDP. Ten percent of the annual output from a prosperous, industrialised nation of 20 million people lost by one company over a period of four years.
A lot has been written about Saab’s lack of profitability, mostly in justification of GM getting rid of Saab. But with numbers like that, and all the internal accounting hoo-haa, it’s easy to see that Saab were, at most, just a tiny blip on the corporate radar screen. Jettisoning Saab is like swatting a fly.
In contrast, very little has been said about which brand is the major villain in this 80-billion-dollar sinkhole.
I would love to see the brand-by-brand breakdown and see who’s lost the most. The next time some journo rabbits on about how Saab were just a dead weight, we could then point them in the right direction and let them know that Saab’s philosophy on vehicle design was the way of the future, which GM ignored to their own detriment.
Just a thought.