The Way Way Back
(2013)

The family decides to cut the trip short due to Trent (Steve Carell) cheating on his girlfriend, Pam (Toni Collette). 

While stopping to fill the car with gas, Duncan (Liam James) jumps out of the car and runs back to the water park where he secretly held a summer job.  He challenges his boss, Owen (Sam Rockwell) to go down the tube water slide together so that Duncan can “pass him” (a feat often talked about at the water park but never done).  As the family chases Duncan to the water park, his mom sees his picture posted as “Employee of the month.” Duncan somehow manages to pass Owen in the tubes, making his way out first.  Everyone cheers. 

On the drive back to Albany, Duncan’s mom climbs out of the front seat to sit with her son in the “way way” back of the car.

Thanks ElizLA!