We can never have too many wacky road trip comedies, but they need to involve particular formula to make things extra off-the-wall. Here’s one version: take a no-nonsense youngster — extra points if he’s a millennial completely dependent on technology who doesn’t appreciate how good things are nowadays (a mile uphill in the snow to school, etc., etc.) — and pair him with a zany sex-obsessed octogenarian who just wants to party. And party hard! Where we going? Vegas? Why? Who cares? Such an adventure is set to star Zac Efron and Robert De Niro with a script by John Phillips and direction by frequent Sacha Baron Cohen collaborator Dan Mazer (he’s a writer on Borat, Bruno and The Dictator). The project is going through a bit of an identity crisis at this point — it’s either called Dirty Grandpa or Driving Dick Kelly, depending on which outlet you consult. But the premise is the same no matter the name: Efron will play a very uptight young man with a huge problem: he’s going to marry the wrong woman! He is also tricked into driving his grandfather (De Niro), a retired, recently widowed and — this is important — perverted Army general, down to Florida for spring break. We all know where it goes from there. Spring. Break. Forevahhh. Question: How would Robert De Niro look in a pastel colored balaclava while holding a machine gun? Is there any answer besides amazing?