<human>: Answer by taking a quote from the following article:

Dan Gurney was born to Jack Gurney and Roma Sexton. His father, John R. "Jack" Gurney, was a graduate of Harvard Business school with a master's degree. Dan's three uncles were each MIT engineers. His grandfather was F.W. Gurney who was responsible for the invention of the Gurney Ball Bearing.

Gurney's first career Nascar start was in 1962. In 1963, he drove a Holman-Moody Ford to fifth place in the Daytona 500. Gurney was nearly unbeatable in a NASCAR Grand National car at Riverside International Raceway in California. Four of his five victories came with the famed Wood Brothers, in 1964, 1965, 1966 and 1968, in cars all numbered 121 (a simple graphic addition to the team's traditional "21"). The serial success of the Gurney/Wood Brothers combination did not sit well with NASCAR officials, so in 1967 Gurney signed to drive a Mercury for Bill Stroppe and legendary NASCAR crew chief Bud Moore. However, the 1967 Motor Trend 500 was won by Gurney's teammate, Parnelli Jones, after Gurney retired with engine troubles. He also won the pole for the 1970 Riverside race in a Plymouth Superbird. Gurney also made numerous appearances in NASCAR Grand American stockcars, a pony car division that existed between 1968 and 1971, but these results may have been in races co-sanctioned with SCCA's Trans-Am, where Dan competed regularly for Mercury, and later Plymouth.  At about the time Gurney began making occasional appearances in stock cars in the United States, Dan took a Chevrolet Impala to England and entered it in several "saloon car" (sedan) races. In a race at Silverstone in 1962, he led the local Jaguar drivers handily until a wheel broke. When he returned with the same car for a race three months later, the local club's technical inspectors disallowed his entry.  Gurney and his protege Swede Savage drove factory-sponsored, AAR built Plymouth Barracudas in the 1970 Trans-Am Series. Cutbacks at Chrysler forced Gurney to cut back to a one-car effort mid-season with Savage driving. In his swan song as a driver, in October 1970 Gurney returned for the season finale at his beloved Riverside, finishing fifth.  In 1980, Gurney came out of a 10-year retirement to help old friend Les Richter, the president of Riverside. (Gurney's adoption of the number that became most closely identified with his career, 48, was a nod to Richter's NFL number.) Gurney agreed to drive a second Rod Osterlund Chevrolet for one NASCAR race as teammate to 1979 rookie of the year Dale Earnhardt. For added publicity and supposedly as a condition of allowing Gurney to drive in the race after a 10-year layoff, Richter insisted that Gurney attend the racing school run by former teammate and friend Bob Bondurant (Gurney and Bondurant had shared the GT-class-winning Cobra Daytona coupe at Le Mans in 1964). After Gurney's refresher session, Richter called Bondurant and asked how Gurney had done. "He didn't need a refresher," Bondurant reportedly told Richter. "He was faster than me then, and he still is." Ticket sales surged upon the announcement of Gurney's return. In a Chevy MonteCarlo painted white with blue and carrying his famed number 48, Gurney qualified seventh and easily ran with the leaders. Displaying his usual fluid style, Gurney raced up to second place, and was running third when the input shaft in the transmission let go, something Dan later said he had never seen happen before or since. CANNOTANSWER

What was his nascar career like?
<bot>: Gurney was nearly unbeatable in a NASCAR Grand National car at Riverside International Raceway in California.