Holley Shiftwell (voiced by Emily Mortimer) is a British spy-in-training who is Mater's love interest in the film. She is similar to Sally.
Holley's name is a reference to Holley Performance Products, Inc., a manufacturer of high-performance carburetors and fuel systems located in Bowling Green, Kentucky. Her design has a close resemblance to the Jaguar XJR-15. Her name is possibly also a reference to Bond Girl Holly Goodhead. Her license plate is HS1201, which includes her initials. The number 1201 is Emily Mortimer's birthday in American date order (December 1).
Holley is equipped with gadgets including: (front) projection lamps above headlights that emit a heads-up display, headlight cameras; a (side) right wheel concealed gun and an electro-shock device, a telescoping utility arm, (undercarriage) mounted dual trackball platforms for controlling the heads-up display, and retractable wings for flight.
Source: Wikipedia, "Holley Shiftwell", available under the CC-BY-SA License.