I spied this car on one of my morning walks, and it made me stop and take a picture. If I didn't know the family, I would probably be able to come up with several theories behind the appearance of a pirate flag on a pink car. But this is the best reason I know of:
This family had four girls before they had a boy, so either one of the girls is really into pirates, or they already had a pink play car and didn't want to invest in another one, so they "pirate-ized" the one they already had for their son to ride. It could also be true that the girls and their brother collaborated on this effort, deciding to play "Pirate and Lady Pirates."
Whatever the reason, it struck my fancy, and I hope it tickles yours!