The system that Disney are using now is the trackless vehicle used in Ratatouille and Mystic Manor. Cars Land would be awesome but it's more of the same as Test Track. It's also the same problem putting the Indy ride into DHS as long as Dinosaur still exists. I'd like to see more Pixar in the parks before they decide to replace a popular area in WDW with the theme. I'd put Monsters Inc in the area between TSL and RnRC though as I see a huge show building and it's easier to hide back there. I forget who, but somebody suggested putting an Incredibles land in the currently discussed area which I think has huge potential and there's a sequel coming. I also like the idea of a water ride for the sake of variety.