I'm sure most know this by now: "9" or "K" was was a price line code that allowed Chrysler bean counters to identify and remove any tax from all levels of production. Legal tax avoidance that was the difference in the price of a Patroller/Pursuit and a Similar passenger car. It was tax issues that prevented private sale of a new K code car..and tax issues alone. Anybody could order anything from extra welds on down in a L/M/H. It was not allowed for a non-government individual or business to order a PK car. It had nothing to do with equipment and everything to do with taxes. A 9 or K coded "police car" is a price line discount code made possible for tax exemption. It was nothing else. Any police special equipment could have been ordered on any price line car.
My 1972 Texas Highway Patrol Polara Custom is a great example. Upper trim level passenger car, with special black and white paint, special police options (including A38), special welds and reinforcement of the rear crossmember , roof and seat tracks. DM41P2D vin.