John DeLorean, the brilliant but troubled automaker who arguably was as flamboyant as his car designs, died yesterday at a hospital in Summit, N.J., after a stroke. He was 80.

DeLorean, the son of an autoworker, reached the executive ranks of General Motors with an astonishing series of successes that revolutionized the industry. He attributed his rise largely to an acute cultural awareness missing in older executives he saw around him, men he once described as "sitting behind (a) desk, wearing a pair of those old high-top leather shoes and packing a big wad of cigars" in their shirt pockets.

His winning formula was strikingly simple and hip: Listen to rock and roll radio. From there, he said, one could gauge what young buyers want, what trends would develop. "It's the cheapest education you could get," he once said.

He won acclaim by introducing sports-car sexiness to conservative Pontiac with his GTO muscle car in the 1960s. He also brought Pontiac its first compact vehicle, predicting a trend to more fuel-efficient models. Ceaselessly inventive, he was credited with creating the overhead-cam engine, concealed windshield wipers, the lane-change turn signal, vertically stacked headlights, racing stripes and an emphasis on cockpitlike driver consoles. He claimed he had more than 200 patents.

He conveyed a manic, restless energy at GM, where he was viewed as Chevrolet's savior after extensive decline for that brand. But he felt constricted by bosses who he said were out to get him and deliberately stymied his plans to improve cars and increase sales. If GM's sales were below 50 percent of total U.S. sales, he said, the federal government would not have any incentive to dismantle the company.

With his overconfident, often dazzling demeanor and a string of innovations behind him, he widely had been expected to take over GM one day.

Instead, he left to form his own, eponymous company with the hope of creating an economical, "ethical" sports car. The British government gave nearly 100 million pounds to the business, hoping DeLorean's plan to employ 2,000 workers near Belfast, Northern Ireland would cause support to dwindle for the Irish Republican Army.

DeLorean's dream was crusted with problems with the start, from undercapitalization to mechanical flaws in the car's design. It took seven years to create the DeLorean DMC-12, a sleek sports car with a stainless-steel body, gull-winged doors and a rear-mounted, V-6 fuel-injected engine.

The cost overruns raised the sticker price to more than $25,000, well beyond the reach of most car-buyers in 1981. The British government, under Conservative Prime Minister Margaret Thatcher, demanded DeLorean raise more money to keep the project solvent. When he was unable to meet the price of business, the plant closed in late 1982, having produced about 9,000 cars.

Embittered, DeLorean went after the Thatcher government with the gusto with which he previously attacked GM. Business had been flourishing, he wrote on his resume, but, "The UK government closed (the plants) because the Catholic employees were said to be tithing to the IRA."

Returning to the United States, he became embroiled in a drug sting operation and was arrested in a Los Angeles hotel room in October 1982. He faced more than 60 years in prison.

Law enforcement officials said he intended to sell $24 million of cocaine to prop up his flailing auto business. To them, the case was clear-cut, complete with an FBI surveillance tape of DeLorean accepting a suitcase containing 55 pounds of cocaine and telling an undercover agent that "it's better than gold."

A series of maneuvers by DeLorean's legal defense team discredited the star witness, a convicted drug dealer turned government informer. Their main argument was entrapment by the government. DeLorean was acquitted on all drug charges and beat a later indictment on charges of defrauding investors in his company.

"We didn't need our extensive defense plan," he later wrote in his 1985 memoir, "DeLorean," by which point he said he was a born-again Christian. "My enemies had destroyed themselves in their effort to be my undoing."

John Zachary DeLorean was born Jan. 6, 1925 in Detroit. His father was an Eastern European immigrant who disappeared from the family, leaving DeLorean's mother, an Austrian immigrant, to provide for their four sons. The one luxury in DeLorean's life was music lessons, which helped him win a college scholarship.

After Army service during World War II, he graduated from the Lawrence Institute of Technology in Detroit. Later, while taking night classes, he received a master's degree in mechanical engineering from the Chrysler Institute of Engineering and a master's degree in business administration from the University of Michigan.

One of his earliest jobs was at the Packard Motor Co., a luxury-car maker. There, he developed an innovative automatic transmission system that he called the "ultramatic."

DeLorean made the leap to Pontiac in 1956 and became director of advanced engineering.

His designs for the Catalina and Bonneville won praise from notable auto racers. His compact Tempest model was named "car of the year" by Motor Trend magazine in 1961, the year he was promoted to GM chief engineer.

His greatest early venture was the GTO. "Little GTO," a song extolling the car's power, became a hit for Ronnie and the Daytonas. The car took its name from a Ferrari coupe called the Gran Turismo Omologato, but the design owed to fitting the powerful 389-cubic-inch, V-8 engine of the Bonneville into the smaller body of the Pontiac Tempest/LeMans.

The manufacturer sold all 31,000 models by the end of the year, and the car continued to be a major moneymaker for years.

In 1969, DeLorean was asked to take over GM's flailing Chevrolet division. He cut administrative staffing at the top ranks and spent heavily on testing vehicles. He introduced the compact, fuel-efficient Vega, but otherwise found many of his proposals dismissed by his bosses.

He became a GM vice president in 1972.

In 1973, he resigned his $650,000-a-year position. He helped business reporter J. Patrick Wright on a book-length expose, "On a Clear Day You Can See General Motors," but then retreated from the agreement with Wright. An unauthorized version of the book, published in 1979, was heralded for its insight.

The nearly 40 legal cases stemming from the death of the DeLorean Motor Co. took years to sort out. He declared bankruptcy in 1999.

More recently, DeLorean sold pricey watches over the Internet under the brand name DeLorean Time.

It was his hope one day to sell new models of the DeLorean sports car, which became a cult favorite after starring as a time machine in the film comedy "Back to the Future" (1985).

His marriages to Elizabeth Higgins, and two models, Kelly Harmon and Cristina Ferrare ended in divorce. Survivors include his fourth wife, Sally; a child from each of his second, third and four marriages; three brothers; and two grandchildren