Ford LTD can refer to either of two similar castings:
Both vehicles are based on the real life Ford LTD, which saw extensive service in the United States as both police cars and taxis. It is therefore no surprise that Matchbox's Ford LTD Police Car is closely related to their Ford LTD Taxi, with both cars sharing the same base. The base only indicates that the model is a Ford LTD without specifying either the police or the taxi variant.
The interior plastic is also the same for both models: details such as the lollipop lights on the rear deck and the box on top of the dashboard (a radio or switch panel for the police car, or a radio or fare counter in the taxi) apply equally well to both models. The car bodies are slightly different to allow for the addition of the lightbar on the police car, or the taxi sign on the taxi. The police version of the casting also includes a radar gun mounted along the top of the right rear window.