His best finish was 3rd position during the 1971 competition in which he drove the Ferrari 512M. He won the 1975 12 Hours of Sebring, teaming with three other drivers. He participated in two Formula One world championship events, the 1971 and 1972 United States Grand Prix, retiring from the first and finishing 12th in the second, thus not scoring any championship points. He drove Surtees cars on both occasions, but only the first was a works-entered car. He also competed in a single event in the NASCAR Grand National Series (now known as the NASCAR Cup Series), the first race of the 1970 season, held on the Riverside International Raceway road course in Riverside, California. Racing analyst Posey went on to become an auto racing commentator for ABC Sports. Posey debuted on ABC for the Indianapolis 500 in 1974, serving as analyst. In subsequent years, he served as a pit reporter, and ultimately returned to the booth starting in 1982. While commentating the 1986 Indianapolis 500, as there was a yellow flag out very near the end of the race, Posey used a two-way radio to ask an impromptu question to race leader Kevin Cogan. Posey was trying to ask Cogan about his thoughts in leading the Indianapolis 500 at this stage. Cogan tried to stave off the conversation once, but Posey persisted a second time, at which time Cogan politely replied to Posey that he was "a little busy now," but would talk to him later. Posey understood the circumstances and told the audience if that were he, "I wouldn't want to talk to me either." Moments later, on a restart with two laps remaining, Bobby Rahal jumped Cogan on the restart and went on to win. Along with the Indy 500, Posey's ABC Sports duties included commentary for the CART/PPG Indy Car World Series with Paul Page and Bobby Unser, lasting through 1995. Posey also appeared on selected NASCAR broadcasts on ABC. The three-man booth of Page, Posey, and Unser was a fixture of Indy car racing during the late 1980s and early 1990s. Posey and Bobby Unser were known to engage in friendly, but sometimes heated exchanges on-air. The friction reached a level such that beginning in 1993 at the Indy 500, Unser moved out of the booth and began reporting from a remote location in turn two. In 1989, Posey was brought in as part