Leak Less Drip Pan
This easter egg can be seen in all versions of the movie.
The second day we see WALL-E working to clean the planet, he puts his cooler down and opens it to collect cool stuff he may find. As he throws an old yellow ducky inside, to the right of the cooler you can see an orange Leak Less oil pan.
Leak Less is a company in the Car‘s universe that makes “Oil pans for adult cars” (adult diapers), and is a sponsor of the Piston Cup with the car Claude Scruggs (#52) driving for them.