Major movie in MA needs to rent a 1971 Buick Estate

Ha, I'd never seen that ad. Here's the poster for the movie:

 

I wonder if they actually found a car to use, took promotional photos, then realized how the seat worked and changed it for the movie? You can see the kid sitting backwards so he's either sitting on the floor or more likely they just photoshopped him in there, which makes me wonder if they even found a car at all or just used a stock photo.