I just did a rough analysis of the Ford and GM's 2008 Financial statements. GM is far worse than Ford. Roughly for every $1 that GM received in Sales it lost 1 cent. While Ford gained 13 cents for every $1 in Sales. So in other words Ford may not have made a record profit, but at least they made some money. GM is in the RED all day long.
There are two reasons, if I were a gambling man, that I would invest in GM still. One... I think that the Government will not allow GM to fail because GM is such a huge corporation that if it fails, alot of the companies that they buy their Raw Materials from will possibly go bankrupt as well (ie, the same companies that Ford, Chrysler, etc. buy their raw materials from). Which could pull Ford and Chrysler along with other companies down with them because they will have to scramble to find other sources.
TWO... I don't know how true this is, but it certainly wouldn't surprise me. China and possibly some other countries have shown an interested in buying GM, which the government does NOT see as a good thing because in certain war time instances what do some GM factories help to produce... weapons, tanks, planes, etc. If China owns alot of factories than we have less places to build certain wartime necessities.
Having said all, everything I have said is my own opinion, if you go out and bet the farm and 2 weeks later GM goes under... sorry. Make your own decisions about what companies to invest in, like Evan said, do a little research into the finacial statements that is what truly tells you how a company is performing.