They took out Ratatouille, because of the trolley lines. The Float was too tall and couldn't be modified. The Incredibles float was easier to modify. All they had to do was move Jack Jack.
At the very very very end of most parades Mater is actually the last vehicle to drive through, and he basically lets everyone know that the parade is over. But they are still adding to it, maybe Cars will get their own floats in the future.
There really isn't a good rout for that, unless they went through Grizzly Peak and Condor Flats, but those pathways are too narrow, and conflict with other shows. I do agree that ELP needs to come back. I miss that show. But I think the Pixar parade is cute. :) I hope that they add Brave to the parade, I think it would be cute.
