The term 'police car' can be broken down into two crossword solutions: UNIT (4 letters) and TIJUANATAXI (11 letters). UNIT is a term used to refer to a group of people or things that are organized together for a specific purpose. In this case, it could refer to a UNIT of police officers in a police car. TIJUANATAXI is a slang term for a police car in Mexico. It is derived from the city of Tijuana, which is known for its high crime rate and police presence.