75% of couples who have taken a road trip vacation, (a vacation where they drive) have experienced this while on their trip. What is it?

75% of couples who have taken a road trip vacation, (a vacation where they drive) have experienced this while on their trip. What is it?

75% of couples who have taken a road trip vacation, (a vacation where they drive) have experienced this while on their trip. What is it?
Ans: They’ve argued!