While driving at a high rate of speed southbound on Mill Creek Drive, the woman lost control of the car, hit a curb and crashed into a tree in the 22900 block of Mill Creek Drive at about 8:15 a.m. She was declared dead at the scene.
"It does appear that speed is the primary cause of the accident," said Jim Amormino of the Orange County Sheriff's Department.
The prospective buyer, identified as an adult male, was transported to a hospital with moderate injuries. Officials said he complained of chest pains.
It is unclear how fast the woman was driving, but the speed limit is 30 miles per hour in the area. The impact of the accident almost split the car in two, with most of the damage to the driver's side of the vehicle.
"I've lived at this apartment and condo area for 13 years, I've lived in this whole area for 25 years, never in my life, ever seen on a 30 mile-an-hour street, any car damaged like that," said Cathleen Neuer of Laguna Hills.
The woman's name has not been released, pending notification of next of kin.