We have already taken a look at the huge drop in year over year unit sales in autos, but month over month unit sales tell a different story. Saturn, GMC, Buick, Pontiac, Hummer, and Chevy round out the biggest drops. Why? A lack of financing. Per the Associated Press:
Neff said a key factor in the GM slump was that its finance arm, GMAC, majority owned by Cerberus (which owns Chrysler) "decreed it would only lend money to buyers with a credit score above 700, which effectively wiped out in-house financing for the majority of GM customers."
Source: Auto Blog