Fillmore's Fields is a farm owned by Fillmore, which you can hit exploding haybales, and tip tractors. Throughout this area there are rusty drums and corn, that you could've picked up for ten Car Coins each if you have completed Mater's Junk Quest. Also there are two fields for tipping tractors. In one of the fields, Frank is there and if he gets you, your Car will be flung out a little ways. The other field has tractors that fall asleep. When you honk at the tractors, they make funny noises and tip.
The location of Fillmore's Fields is actually where iWorld of Cars will put mountain roads northeast of Radiator Springs. The "new" Fillmore's Fields will be located in the Ornament Valley area but a bit north of Ornament Valley.
Northwest - Willys Butte
South - Radiator Springs