Anyone of a certain age will recall the 'National Lampoon Vacation' movies. The first one saw Chevy Chase trying to take his family on an old fashioned road trip to a far off amusement park, and the second one, Christmas Vacation, still does the rounds every year.

In a somewhat surprising sequel, Ed Helms plays Clark's son, Rusty, in a (even more surprisingly) funny looking follow up.

Christina Applegate, Keegan-Michael Key, Chris Hemsworth, Leslie Mann and Charlie Day also pop up; while the flick was written and directed by Horrible Bosses pairing John Francis Daley and Jonathan M. Goldstein.