The way it was explained to me, in part, was that if you have an automobile that could retail for $23,000 and you choose to sell it for $25,000 and give away free financing, you're essentially taking your profit as the manufacturer as opposed to the credit company. The credit company for the automobile manufacturers is essentially part of the production and sales cycle of the manufacturers. The credit company is there to help move vehicles, so instead of taking a profit at the credit company level, you are taking a profit at the manufacturer level. It all comes out in the wash.
On March 31st, 2009. See this statement in context.