The Beautiful Summer(1974)

A mother keeps making excuses for why her son's father has not returned home. Jon Marco, just celebrating his ninth birthday, concludes his parents have separated and develops a plan to place himself in dad's care. Along with a new friend they run away to Milan to search for Marco's father. Once executed, our little hero learns the truth about his famous race-car driving father. Can mom and his pals help him deal with the trauma?