List of defunct U.S. auto manufacturers
From Wiki, <a href="http://en.wikipedia.org/wiki/List_of_defunct_United_States_automobile_manufacturers>List of defunct manufacturers.
A first, quick (sorta; it's a long list) glance, it doesn't appear that many went under during the Great Depression, but this source claims:
After 1930, the number of auto manufacturers declined sharply as the industry consolidated and matured.
Hmmm. 'Guess the GD didn't have anything to do with it.
S