DETROIT - Nine million parts.

That's what General Motors needs to repair millions of cars it has recalled since Feb. 7. With ignition switches, power steering motors, and other parts slowly arriving at dealers, frustrated drivers face waits of weeks or months, some while driving cars they fear are unsafe.

Any recall can present challenges for automakers and customers. Still, most recalls involve fewer than 50,000 vehicles and are typically completed in two or three months.

But experts say eight simultaneous recalls covering 7 million vehicles is too much for any organization to handle quickly, even one as big as GM. Suppliers have to make the parts - there aren't millions in stock. GM has to notify customers, ship the parts to dealers worldwide, and train mechanics how to do the repairs.

GM says it will take six months to make and distribute all the parts for the largest recall: 2.6 million small cars with faulty ignition switches that the company links to 13 deaths. The switches, mainly in older Chevrolet Cobalts and Saturn Ions, can slip out of the "run" position into "accessory," shutting off engines and disabling power-assisted steering and air bags. GM has told dealers to offer concerned owners loaner cars while they wait for parts.

There's no estimate yet on when the other recalls will be finished.

"This is a big old hot mess," said Blair Parker, a Houston-area lawyer who owns a 2005 Chevrolet Cobalt included in the switch recall. Her dealer can't tell her exactly when parts will arrive.

All told, the recalls present a herculean task for GM. Multiple suppliers are involved, and parts need to go to more than 4,300 dealers.

Dave Closs, chairman of the Supply Chain Management Department at Michigan State University, says GM dealers will have frustrated customers on their hands for a while.

Toyota is in a similar situation. Last month, it announced recalls totaling 6.4 million vehicles to fix defective seats and bad air-bag wiring.

Bob Carter, Toyota's U.S. automotive operations chief, says car owners can expect more frequent recalls because the regulatory and competitive environments have changed. Instead of recalling cars for known defects, companies are now "recalling vehicles to change problems that we anticipate might happen," Carter said.

GM is under fire because it knew about the problem with the ignition switches for 10 years before conducting the recall. Two congressional committees, the Justice Department, and federal safety regulators are investigating GM's slow response, and criminal charges are possible. GM has hired lawyer Kenneth Feinberg to negotiate settlements with surviving families and some injured drivers.

GM dealers say small numbers of parts began arriving late in the week of April 7, and the pace has picked up. GM says it has shipped thousands of ignition switches and notified 1.4 million owners to set up repair appointments.