In what is set to become a terrible domino effect, lagging demand for new cars and an uncertain future at Hummer, Saturn and Saab dealerships is leading to an inventory pile up. That, in turn, means dealers are ordering no new cars, driving General Motors' production schedule even further out of alignment.

Output in the first quarter was down 57% across GM's U.S. operations, or about 500,000 vehicles short of Q1 2008's output. That is a major decrease in new cars being produced, but it's still outpacing dealers' ability to move the cars off the lots, reports The Detroit News.

"If they tell us what they're going to do with the brand, we'll tell them when we're thinking about ordering new vehicles," said John Java, a Saturn dealership owner. "We're starving to death."

Overall, GM's inventory levels have fallen somewhat, to about 781,000 vehicles, a decline of about 20,000 since January. But despite dealer uncertainty and a still very large supply of inventory, GM is planning to actually increase production to 550,000 cars in the second quarter, though the figure is likely to be reduced as sales continue to stagnate.

Other carmakers are feeling the same pressures as GM, but in smaller magnitude. Ford, for example, has chopped its standing inventory by about 33%, while even Chrysler has shaved almost 20% of its stockpile of cars and trucks. By comparison, GM's decrease of 17% since 2008 is on the low side.

The only thing that can really turn the situation around, however, is increased sales. Government stimulus packages and carmaker incentives are doing their best to drum up demand, but in the end, it will come down to the American consumer to snap out of the slump.