In California, a vehicle is presumed to be a “lemon" by the Song-Beverly Consumer Warranty Act if, within 18 months of the vehicle's delivery to the buyer (or 18,000 miles on the odometer):
- 2 attempts or more have been made by the manufacturer to repair a warranty problem that could result in death or serious injury.
- The manufacturer has attempted to repair the same warranty problem at least 4 times.
- The car has been out of service for 30 days or more for repair to warranty problems.
- Problems to the vehicle are not the result of abuse by the owner.
http://www.dmv.org/ca-california/automotive-law/lemon-law.php