As you can probably imagine, police vehicles live a very tough life. They cover high mileages and even cars like the Shogun will have almost certainly engaged in high-speed pursuits. Also the occupants of the rear seats tend not to care too much about their surroundings. On the flip side police cars have to be well-maintained in order to survive the abuse they go through.

The key factor here is price. If you're looking for the absolute cheapest Shogun you can find, then an ex-police vehicle is probably the best option. But would it be worth spending a few extra hundred pounds to buy one that previously owned by a regular driver and that had enjoyed a normal life?