I thought the truck was in the scene where Syndrome's robot lands in the city and starts smashing things, or in the scene where the Incredibles land in the RV??? Where were you looking for your information/list of the "crossovers"? I forgot to look at Monsters University, I was too busy watching my kids watch the movie... LOL
Where is the truck in Brave?
Nearly every Disney movie has a cross over to another movie. They've been doing it for a long time. Most of them are not obvious at all until it's pointed out.