Courtesy of Bonhams

A hitchhiker found the body in the sand beside Highway A1A near Jacksonville, Fla., next to the fatal .38. A briefcase held the sales receipt for the pistol and a suicide note, timed 2:30. Precise as ever, even in death, was “Peter Perfect,” the golden boy race driver, Peter Gregg, dead at age 40.

Gregg’s tragic story, reported in December 1980 by The New York Times (PDF), was wrapped up with his BMW M1, which is expected to be one of the most closely watched vehicles at the Quail Lodge in California next week, when Bonhams offers the M1 at auction during the Pebble Beach collector-car festivities.

The car belongs to the Guggenheim Museum in New York, which is selling it to finance other acquisitions, according to Bonhams. The presale estimate ranges from $450,000 to $600,000.

The one-of-a-kind racer was painted by the artist, Frank Stella. It was specially ordered by Gregg, a six-time world champion in the International Motor Sports Association. Bonhams’ catalog presents the car as essentially a BMW art car, the only one not owned by the company.

The story begins when Mr. Stella was asked to paint an art car for BMW, a 3.0 CSL, in 1976. The next year, Mr. Stella traveled to Europe to watch the car compete, where he met the Swedish driver Ronnie Peterson and Gregg, the men who raced it, and visited Le Mans and the Nürburgring.

Mr. Stella began to follow motorsports. In February, he visited Daytona International Speedway to watch the 24-hour race there and began traveling with the BMW Formula Two racing team in the fall of 1978. He and Gregg were present at Formula One grand prix at Monza, in Italy, when Peterson, Gregg’s teammate, was involved in a crash. A few hours later he was pronounced dead, and Mr. Stella dedicated his “Polar Coordinates” series of paintings to Peterson’s memory. The M1 is dedicated to Mr. Peterson as well.

Designed by Giorgetto Giugiaro, the M1 was inspired by Paul Bracq’s Turbo concept and was BMW’s first supercar, with a race version modified into a street model. Gregg ordered his unit from Munich in 1978, specifying the Black Watch Tartan pattern for driver and passenger seats. In 1979, Mr. Stella devised the paint pattern for the car, a version of the theme used in his “Polar Coordinates.” He painted and signed the car in Jacksonville, where his autograph was protected with clear coat.

Gregg, a graduate of Harvard, also was a squash and tennis star before he took up racing in the late ’50s. He settled in Jacksonville after a stint in the Navy brought him to Florida and became a car dealer specializing in Porsches and other European makes. He was a member of bank boards and an accomplished sailor at the Ponte Vedra Yacht club.

Michael Cannell, the author of a coming book on racing entitled “The Limit: Life and Death on the Grand Prix Circuit,” said in a telephone interview that Gregg was a popular and telegenic figure whose career ended in step with an era where racers could become romantic figures. “The constant presence of danger made them like fighter pilots or rock stars,” Mr. Cannell said.

In June 1980, Gregg, with Mr. Stella in the passenger seat, headed for Le Mans, where Gregg was due to race in the 24-hour race there in a 924 Carrera GTS for the Porsche factory team. According to several accounts, Gregg encountered an oncoming car while attempting to pass an oxcart. To avoid a collision, he maneuvered his vehicle into a ditch, sustaining injuries. After his recovery, Gregg experienced persistent double vision that effectively ended his racing career and, associates said, left him depressed. “I just don’t enjoy life any more,” his suicide note read in part.

According to Bonhams, the car was sold in 1990 by Gregg’s widow and was donated by its then-owner to the Guggenheim in 1999. It has been driven on only a few occasions, notably by the racer Jochen Neerpasch, who drove it with Mr. Stella as his passenger in a Pro Car M1 racing event in 2003.

“Sport and art have one key thing in common: in the end it comes down to satisfaction,” Mr. Stella says in the Bonhams catalog. “My philosophy is: always give of your best. Sometimes I’m surprised at what turns out, at other times I’m disappointed. Out here on the racetrack it’s very hard not to be thrilled.”

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