Answer: Clark
In the very beginning of the movie, Clark and Rusty take their old station wagon to the car dealership, in order to trade it in for a new car. When they get there and ask for their new car, the dealer shows them a hideous station wagon he calls "the Wagon Queen Family Truckster" in an even more hideous color, "Metallic Pea". Clark tells him that he's not interested in that car, and just wants the car he ordered, the super sports wagon. However, the dealer tells him that it didn't come in, so Clark gets angry and asks to have his old car back. When he gets it back, he finds that it has already been demolished, so he must take the Wagon Queen Family Truckster instead of the car he actually wants.