It's the Girl in the Red Truck, Charlie Brown Sep 27, 1988

Spike waves to a young woman driving a red pickup truck through the desert of Needles, California every day; it is the highlight of his day. In this combined animated and live-action special, we meet an aerobics instructor, Jenny, who wants to be a big city jazz dancer. She and Spike drive around looking at the desert scenery and spending some time at a roller rink. However, when Spike is accidentally thrown out of the skating rink he runs off and is pursued by people on a nighttime coyote hunt.