Broken down VW Bug ( the old type)

A lady broke down on the highway in her VW BUG. Just as she opened the front hood and looked in and saw nothing, another lady pulled along side of her VW BUG and asked her what was wrong. The first Lady exclaimed " my car stopped running and I think I know why, there is no engine" The second lady said "that's alright I have a spare engine in the trunk"