There's a 15 minute "film school" on different aspects of filming - they breakdown how doing a overhead camera swing around the car wasn't possible without 360 degrees of green screen, so instead they only moved the camera straight up and down and rotated the car by placing it on a cart, creating the final effect.
Of course with the visuals you'd figure there's a lot of green screen, but when you actually see how little the actors had to work with it's astounding. When Bruce Willis walks through an open doorway into a room, the only thing on the set besides green screen is the door (no walls or anything else) and a few piles of papers on the ground that get blown around by a fan. Nothing else. When Hartigan is running through a forest, they cut back and forth between what they filmed and what the final product looked like. With CGI you have a complete forest, snow, and everything. With no changes, you simply have Bruce Willis running against a green screen on a green treadmill.
Apparently Mickey never acted with Elijah Wood even though they have a fight scene in the movie. They showed filming Mickey's reaction to getting kicked in the face, and then combining that with footage of Elijah kicking filmed a few weeks later.
Another nice feature lets you see the setup between takes, as they did one long take where they actually did adjustments while the camera is rolling. You hear Tarantino yelling, "Great! Where the fuck is makeup?" as they're waiting to get an effect just right.
And of course, what kind of special features disc would be complete without a 10-minute cooking school, describing how to make the breakfast burritos they would make when they were up late filming? And you know it's going to be good when they start out with "take the flour tortillas you got from the store - the ones that feel like rubber - and throw them out. We're going to teach you how to make your own."