When Jason starts going on about whatever car has caught his fancy. http://www.youtube.com/watch?v=vg1JUZ9wlGU&feature=related
And that's only the first half. By the time I get to the last half, I'm dying no matter how many times I watch it with Madeline. It's on the Pixar Short Films DVD.
Dang you Tam...Been having a time with heartburn today and finally got it controlled until I watched that clip...laughed so hard....