Anoka County Sheriff's officials said the 34-year Circle Pines woman reportedly crashed into a fence behind the store at about 7 a.m. Sunday.
The woman's name has not yet been released.
No additional information about her cause of death has been issued. The sheriff's office, Blaine police and the Midwest Medical Examiner's Office are investigating.
A store manager had discovered the woman early Sunday, FOX 9 reported. Police said she was found slumped over the steering wheel.