Lemon Laws are state laws governing the rights of purchasers of new and used motor vehicles that are defective, do not function properly, and which have to be returned repeatedly to the dealer for repairs.
Lemon Laws protect consumers from substantial defects occurring within a specified period after purchase and provide that a manufacturer must either replace the lemon with a new comparable car or refund the full purchase price
California's consumer protection laws protect the consumer who purchased a vehicle with a manufacturer defect which affects the safety, value, or use of the vehicle and the defect can not be repaired within a reasonable number of attempts by the manufacturer or the dealership. Also, the repairs must occur within the original warranty period supplied at purchase. Any used vehicle sold with an unused portion of the manufacturer's new car warranty may also qualify to be covered.
The California "Lemon Law" presumption is merely a legal device which is only meaningful if negotiations with the manufacturer fail and you must resort to litigation. It then allows the consumer/plaintiff to establish at trial that he or she has met the plaintiff's normal burden of proof, that the vehicle is a lemon shifting the legal burden to the manufacturer to prove otherwise.
The presumption is neither a requirement nor a prerequisite. There are many situations which do not exactly meet the "Lemon Law" presumption, but which may still entitle you to recover under the "Lemon Law". So long as the defect affects safety, value, or use, and occurred within the warranty period, and cannot be repaired after a reasonable number of attempts, the vehicle is entitled to these legal protections.