Automakers boost production, but for how long?

The popularity of the Obama administration's "cash for clunkers" is leading General Motors to boost output at three plants that make compact and midsized sedans. GM is adding shifts in plants in Ohio, Michigan and Kansas that make its Chevrolet Malibu and Cobalt, Saturn Aura and Pontiac G5 and G6 sedans to replenish depleted stocks of newly popular vehicles. Ford (F) and Chrysler are also increasing production, as are foreign car makers Hyundai, Toyota (TM) and Honda (HMC), all of which operate plants in the U.S.

Foot traffic at the nation's new-car showrooms has picked up considerably since the inception of the program last month. Consumers, eager to cash in on rebates of up to $4,500 when they trade in older, gas guzzlers, have picked dealers' lots clean of some models, necessitating that auto makers increase production to replenish them. The most popular models include the Toyota Corolla and Ford Focus, both of which get as much as 35 mpg, according to EPA estimates.