In a brief flashback to Fat Amy's youth, she is wearing a My Little Pony shirt. But this shirt has the modern "Friendship Is Magic" versions of the characters; that generation of the franchise would not debut until many years after Fat Amy was a little girl.
When the girls are kidnapped, the black Mercedes Bus is initially clearly shown with a French format number plate for the Alpes Maritimes department in the south of France (CZ-081-GZ). However a few seconds later we see the number plate has changed to a different number (RY62DFD) with the department badge missing. RY62DFD is rather oddly a UK format number plate.