June car sales plummet; more declines expected

That includes Toyota, which didn't have enough of its fuel-efficient Prius, Corolla or Yaris cars at dealerships to keep up with demand. Prius sales were hurt by a battery shortage, while sales of the Corolla and Yaris suffered because of plant capacity.

When consumer tastes change as quickly they have this year, it's tough for automakers to react in a matter of months. Additional workers have to be brought in to factories and trained to build different cars.

Ford has been trying to raise output of the lone factory near Detroit that makes the Focus compact but still couldn't meet demand this month. Both GM and Ford have announced plans for new subcompacts, but it will take at least two years to gear up factories for the new products.

"That just shows the market forces changed extremely fast. No automaker was ready for it," Toprak said.

Only Honda, whose lineup is tilted toward smaller and more fuel-efficient cars, reported a sales increase for June--slightly over 1 percent. Honda car sales were up nearly 20 percent, truck sales down 24 percent.

Elsewhere, the picture was far worse. Nissan Motor Co. reported sales off nearly 18 percent. Sales at Ford, which still relies on trucks and SUVs, plunged almost 28 percent. And Chrysler LLC took a huge hit--down nearly 36 percent.

To help boost sales, Chrysler said it would extend its offer of $2.99-per-gallon gas through July 31. It had been scheduled to expire July 7. Chrysler pays the difference between $2.99 and the pump price for 12,000 miles a year under the offer.

The promotion started in May, but car sales at Chrysler still fell by almost half. Its truck sales dropped 30 percent.

The overall market dropped to 1.19 million vehicles sold, down more than 266,000 from last June. U.S. car sales were down about 10 percent for the first half of this year.

Ford sold 41 percent fewer of its perennial best-seller, the F-series pickup truck, and it sold fewer than half the number of Explorer SUVs as it did in June 2007.