1
general::
Phrase(s): pile someone into something [and] pile someone in
to bunch people into something in a disorderly fashion. • She piled the kids into the van and headed off for school. • She piled in the kids and closed the doors. • Pile them in and let’s go. • They piled themselves into the car and sped off.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Move in a disorderly group into, crowd into, as in The team piled into the bus. The related expression pile in takes no object, as in Jack opened the car door and yelled, "Pile in!" [First half of 1800s]
American Heritage Idioms