Maggie Peyton is the protagonist in Herbie: Fully Loaded.
Maggie loves racing, but her over-protective widowed father, Ray Peyton, Sr., tries his best to keep her away from the life of racing because of a life threatening accident she had long ago.
The day after graduation, her father brought her to Crazy Dave's junkyard to buy her a car. When Herbie saw her and her passion for racing he grew a liking towards, and after many attempts to gain her attention, she bought the little car.
During her first drive, she thought about sending Herbie back because of his unexplained and embarrassing tricks on her, but after he helped her beat the NASCAR champion Trip Murphy in a road race, she changed her attitude towards him and the two became friends.
She secretly enters Herbie in a drag race posing a masked race driver named Maxx. Unaware to the two of them that the whole thing was set up so Trip could learn about the little car's secrets and get even. When Herbie saw Maggie take a joyride in Trip's NASCAR, and said it was the best ride ever, he became quite jealous and deliberately lost their final race to Trip. Maggie reluctantly reveals her identity to public, and loses Herbie, who gets taken to a demolition derby.
Maggie manages to save him, and after her brother Ray Jr. gets hurt during practice, he suggests Maggie should take his place, but her father is still against it. However, they proceed to go ahead with it, and fix up Herbie for the race. Together, they take on the toughest tricks that the other drives throw at them and win.
Maggie and her closest friend, Kevin, later become a couple and share their first kiss.