Stephanie Jerauld thought her silver BMW died the day she smashed into the trailer of a landscaping truck on Old Keene Mill Road in Fairfax County. An air bag protected her from serious injury, but with the car's hood shorn in half, the windshield shattered and the side crumpled, the insurance company pronounced it a total loss.

"I was in shock," said Jerauld, 31, a Fairfax County teacher. As she collected school papers from the back seat after the collision on Oct. 18, she was sure the BMW had reached the end of the road. "I thought it would be sold for parts," she said.

Instead, the road went on for 4,000 miles. Meet Pedro Portillo, 40, a lawyer with lifelong dreams of cruising San Salvador in a Bimmer. "Since I was a little boy I have wanted to own one," he said. Now he does -- the rejuvenated 328i that once belonged to Jerauld.

A flourishing trade is transforming cars sold as junk in the United States into cherished gems on the streets of Central America. Tens of thousands of damaged cars written off for a few hundred dollars in the north find a new life here to the south, arriving via a network of middlemen and often repaired by mechanics in backyard workshops.

Jerauld, like most of the cars' original owners, said she had no idea what happened to her car after her insurance company had it hauled away. New owners here also rarely know anything about the accidents that set U.S. cars on a journey toward them.

"What? The body shop said it was heading to the junkyard!" said Latasha Andrea Milton, an office processor in Baltimore, when a reporter telephoned her to say her 2000 Hyundai Elantra was in a repair shop in El Salvador. She said a driver smashed into her Hyundai last summer while she was on her way to church. "I never thought somebody in another country would be driving my car. They said it was a total loss."

With more than 6 million car accidents a year in the United States -- and an average of 91 a day in Fairfax County, according to police -- there is an ever-growing number of U.S. cars deemed by insurance companies too expensive to repair. Especially since the introduction of air bags, which can cost thousands of dollars to replace, the cost of fixing even superficially damaged cars has soared beyond their value.

The story of how Jerauld's crumpled BMW ended up looking like new in a lawyer's driveway in El Salvador was pieced together by tracing vehicle registration numbers, car titles, U.S. police accident reports and papers found in U.S. cars exported to El Salvador.

A month after Jerauld's accident, Jose Oscar Cerna was surfing Internet car auction sites from his middle-class neighborhood in San Salvador, a densely populated city surrounded by mountains, when he spotted a smashed BMW. "It really caught my attention," said Cerna, 51, a thin, energetic man with a degree in business administration. "It was ideal, exactly what I was looking for."

Like an estimated 4,000 other entrepreneurs in El Salvador, Cerna makes a living importing damaged cars from the United States, repairing them and reselling them. He traded in his more routine government job eight years ago and hasn't looked back.

"It's never boring," he said.

Cerna immediately telephoned Portillo, whom he knew was in the market for a BMW. The two men studied the picture and description of the car, which was on a large auction lot in Richmond.

Cerna said he dispatched a relative in the United States to inspect it; the conclusion was that while there was substantial body damage, the engine was unharmed. "I was so excited. I really wanted that car," Portillo said.

Cerna did not know who owned the car before, or that Jerauld's insurance carrier had determined it would cost more than $14,000 to repair it. The insurance company paid Jerauld her claim and, as its new owner, had the BMW towed from Redman Fleet Service lot in Fairfax to the Web site's auction lot in Richmond, a popular way station for crashed D.C. area vehicles.

Photos of the damaged BMW were put on the Internet, and its auction date was set for Dec. 6. Hundreds of thousands of cars involved in accidents are sold this way by insurance companies every year.

Cerna was poised to bid. He had found a match for Portillo and now hoped to buy his first luxury car after years of reselling Fords and Hondas.

With competing bidders as far away as Africa, the BMW opened at a price of $4,000.

The offers kept rising. Cerna kept up, topping each counteroffer by $100.

Finally, it was over. "SOLD" flashed on Cerna's screen. He had won it with a bid of $7,405.

"I was so happy," said Cerna, who delights in talking about cars. "It's a great feeling when you win a car."

Five days later, in the pre-Christmas holiday spirit, Cerna was on a plane bound for Charlotte. The BMW had already been paid for with a wire transfer.

Cerna hired a friend and his tow truck to haul the car to Salisbury, N.C., "my center of operations," as he jokingly called it. There, Cerna has many friends and gets cut-rate deals on auto parts and labor. He makes this same trip about eight times a year, flying into the United States and driving out of the country in his new purchase.

He went shopping in Salisbury to make his BMW drivable. The cost of shipping the car by boat would have been about $500; while Cerna has sent many cars that way from the port in Wilmington, Del., he did not want to risk this silver sedan being jostled on a rough sea.

So he bought his BMW a $165 hood, fastened on a new $150 right headlight, installed a $120 windshield and suited it up with new temporary license tags.

"Then came the fun part," he said. He set off for home in mid-December on the smooth U.S. interstates. When he got tired or worried about snow or rain, he pulled over to highway rest areas and slept on the car's soft black reclining leather seats. In Mississippi, he splurged at an outlet mall buying presents from Levi's, Tommy Hilfiger and other shops.

After crossing into Mexico, Cerna drove for miles past the lovely Veracruz beaches on the Gulf of Mexico. "It was like driving on clouds," he said.

On Dec. 20, five days and 3,787 miles later, he pulled into his driveway in San Salvador. He had just imported his finest car. Earlier this month, he was still repairing the BMW, parked at his front door of his home, beneath coconut-heavy palm trees and purple bougainvillea.

It has taken Cerna two months to put the finishing touches on the BMW, pay the $3,600 in import taxes and complete the paperwork for it to be legally circulating in El Salvador. Largely because the labor costs of fixing the car were $700, Cerna has earned a profit of a few thousand dollars for his effort.

Portillo is now the owner of the BMW, having paid $18,000 for it -- as much as $10,000 less than the price a BMW dealership here would charge.

"I finally own it!" said a delighted Portillo, who says next Thursday he will have his new license plates. He says he is already planning to take his family on a four-hour drive to an amusement park in nearby Guatemala. "It's a wonderful place," he said, "similar to Magic Mountain in Los Angeles."

Researchers Alice Crites and Sarah Park contributed to this report.

The owner of this BMW, damaged by a tree and then totaled in an accident, thought it would be sold for parts. Instead it turned up in El Salvador. Jose Oscar Cerna in San Salvador with Jerauld's old BMW, which he bought at an Internet auction, had overhauled and drove to El Salvador for final repairs before reselling it. Stephanie Jerauld was sure her old BMW would be "sold for parts" after it smashed into the trailer of a landscaping truck last October in Fairfax County.