Before turning to racing, Mundy worked as a daredevil performer, including an appearance at the 1939 New York World's Fair. During the Second World War he served as a personal driver for General George S. Patton, an experience he credited with sharpening the driving instincts he would later apply on the oval tracks of the American South and Midwest.
In 1948 Mundy relocated to Daytona Beach, Florida, initially to pursue a career in motorcycle racing. At a service station owned by Bill France Sr. he struck up a friendship with France and was subsequently invited to a 1947 planning meeting at the Streamline Hotel where NASCAR was being organized. At that meeting Mundy assisted the group photographer by holding a flash unit during the now-iconic founding photograph.
Mundy began his NASCAR Grand National career in 1949 and competed through 1956. His career average starting position was 11th and his average finishing position 17th, reflecting a level of mid-pack competitiveness over a field that could number more than 70 entrants in the era's marathon events. He raced a total of 3,583 laps — equivalent to approximately 3,184 miles — and led 458 of them, around 12 percent of his total.
He started from pole position at the 1951 Southern 500, one of the most prestigious events of the early Grand National calendar, though he ultimately finished 82nd as attrition claimed many rivals and he could not avoid misfortune himself. He won three NASCAR Grand National races during his career, with one notable victory coming at the 1955 Southern Illinois 100. His preferred manufacturers were Studebaker and Oldsmobile, and he was frequently seen in cars fielded by the well-funded Carl Kiekhaefer operation, which dominated much of the mid-1950s season.
Mundy attempted to qualify for the 1954 Indianapolis 500 but failed to make the starting field, his sole effort on the oval's biggest stage.
Following a dispute with Bill France Sr., Mundy split from NASCAR in 1952 and redirected his attention to the American Automobile Association (AAA) stock car series and later the United States Auto Club (USAC). The move proved highly successful: in 1955 he won the AAA national stock car championship, claiming the title in the final season the series ran under AAA sanction before it transitioned to USAC governance. He did not return to NASCAR until 1955, effectively competing in both sanctions that year.
Born Francisco Eduardo Menendez, Mundy was of Mexican and Irish descent. He spent his childhood in an Atlanta orphanage and assumed the name Frank Mundy as he embarked on his racing career. After his driving career ended, he joined Penske Racing as a pit crew member, remaining connected to the sport in a supporting role. He was survived by his widow, Mae Mundy, when he died in May 2009 at the age of 90.
Mundy's career straddled two regulatory eras — AAA and NASCAR — and his championship in the final AAA season made him one of the last drivers to hold a title under that organization's banner. His presence at the foundational meetings where NASCAR was structured gives him a small but genuine place in the administrative history of American stock car racing alongside his achievements on track.