In Garrett v. Crown Coach Corp. (1968) 259 Cal.App.2d 647, the plaintiff's vehicle was struck by a school bus. The plaintiff filed an action against the board of education, two school districts, two named individuals, and five Doe defendants. (Id. at p. 648.) The plaintiff alleged that the two school districts negligently operated and maintained the school bus. The Doe defendants were alleged to be the agents and servants of the school districts and acting within the course and scope of their employment. (Id. at p. 649.) The original complaint described the bus as a "'1960 Crown 79 passenger school bus.'" (Id. at p. 650.) Approximately two years after the accident, the plaintiff filed an amended complaint substituting Crown Coach Corporation (Crown) for Doe One. The amended complaint realleged the original cause of action, but added new allegations that Crown negligently designed and manufactured the bus. (Id. at p. 649.) In identifying the issue, which is, in essence, the same issue we face here, the court stated: "The problem in the case at bench arises because the amended pleading seeks to hold Crown upon a theory not spelled out in the original complaint. The first pleading is based specifically upon allegedly negligent maintenance and operation of the bus. The school districts were allegedly responsible for the vehicle, and the other defendants, including Doe One, were alleged to have acted as agents and servants of those entities. The second amended complaint reflects plaintiff's desire to charge Crown as a negligent designer and manufacturer, a theory not revealed by any factual allegation in the earlier pleading." (Garrett v. Crown Coach Corp., supra, 259 Cal.App.2d at p. 650.) The court further observed: "In the case at bench the original complaint, alleging that Doe One was operating the bus as an agent and servant of the school districts, seems to identify Doe One as a person other than the corporation which designed and manufactured the vehicle." (Id. at p. 652.) The Garrett court, relying on Austin v. Massachusetts Bonding & Ins. Co. (1961) 56 Cal.2d 596, held that the amended complaint related back to the date the original complaint was filed because the amended complaint "sought to hold Crown legally responsible for the same accident and the same injuries referred to in the original complaint." (Garrett v. Crown Coach Corp., supra, 259 Cal.App.2d at p. 651.) In so holding, the court acknowledged that, as in Austin, the plaintiff, by way of the original complaint, did not contemplate suing the party she later substituted in. As explained: "The amendment in Austin changed not only the theory of liability, but the factual allegations upon which the asserted liability of the defendant was to be based." (Garrett v. Crown Coach Corp., supra, at p. 652.)