Auto sales, the price of gas and HELOC financing

This story says that one reason auto sales are down is one out of nine new cars sold recently were financed through HELOCs. As I've mentioned before, I think this is a larger factor in the move away from large cars than the price of gas (though both are factors). People are uncertain about the economy, many are unable to get credit at all or at favorable terms, and prices of everything are going up. High gas prices are part of it, no question, but don't think that we would see the current declines in VMT and large car sales without exogenous factors to the marginal cost of driving.