Splash News says that Jessica Simpson was having dinner in Santa Monica on Tuesday night, and when she was done she left in an Escalade limousine. Which would be fine if that limousine was for her. Eventually her fiance followed her to a red light and she got into the right car.
This may be a simple misunderstanding or change of plans, but keep in mind that Jessica has done this several other times before. She'll just climb into any shiny black car. So if you'd like to kidnap Jessica Simpson and get away with it, that's how your plan should start.