[IndieWire]

One of the things that he added for the theatrical presentation of “Spy Kids 4: All the Time in the World,” was a scratch-and-sniff card, and while the cards didn’t make it to this current home video version (“We decided to save it for a future special edition,” he said), Rodriguez told us about the genesis of this aromatic approach to his new movie, which he describes as “4D.”

“The reason for the 4D was because back then I had the first 3D movie in probably 20 years in theaters [not to quibble here but ‘Freddy’s Dead,’ which featured a prolonged 3D sequence, was released in 1991, some 12 years before ‘Spy Kids 3-D: Game Over‘] so I thought we can’t come out with another ‘Spy Kids’ in 3D again and I remembered the John Waters movie [‘Polyester‘] that had some pretty simple scratch-and-sniff cards,” Rodriguez explained. He also noted that it wasn’t a huge financial commitment either since, “Being a John Waters [movie] I figured it couldn’t be that expensive, so it wouldn’t be too hard to replicate some extra value stuff we could give away for free.”

…

See the full interview here: http://blogs.indiewire.com/theplaylist/robert-rodriguez-talks-spy-kids-4-the-joys-of-self-financing-and-his-5-000-upcoming-projects