In late 1959, as bored students returned from summer vacation, the sport of phone booth stuffing morphed into a new form. Volkswagen stuffing became all the rage as students tried to stuff as many people as possible into a Volkswagen car. The fad began in 1959 and peaked in the mid 1960’s when a record 18 people stuffed themselves into a Volkswagen bug. Later other model cars were used and Guinness Book of World Records began recording records for each model of car (along with rules such as windows and doors must be shut for the record to count).
More information on phone booth stuffing, the predecessor to car stuffing, can be found here.