I live in Pennsylvania, which is a rust belt state.
The PA State Police vehicles are handled through a special department of the department of transportation and they have a special facility which preps the vehicles - marked vehicles before they go out on the road. Installs some of the radio's, computers, printer, lights, sirens, badges etc. When they are through with the vehicle, it goes back through their facility and everything is removed and then the vehicle is painted a plain color - usually something other then white and then it is ran through a auction such as the auction in Harrisburg PA.
The County, township, boro, city vehicles are bought through the old GM COPO = where they buy them at a wholesale price because the state goes to the trouble of ordering them for them - say 50 at a time and then the boro's buy them and send them to a place where they get their own paint job and badges. Those people usually runs them until they are no longer reliable. Then they remove all radios and badges and they either sell them at public auction or they put a ad in the paper where you can put a bid in on the vehicle. Usually - you are not allowed to drive it or even start it up before you buy it.
You might could get one pretty cheap, but by the time they are done with it, it is wore out from one end to the other. Generally the oil has been changed as per the lease agreement and then per the mininum standards per their vehicle service plan - after that - it is a crap shoot as to when anything was done or how good it was taken care of.
Some state and local vehicles are by law required to have the back seat taken out after every shift. After 100,000 miles, the interior is usually shot. The suspension is usually wore out and the engine and transmission is shot. The body is all beat up and some things might be broke or missing. The old joke is to never buy a used rental vehicle - because you know what people do to a rental car. Well double or triple the abuse and that is what you get with a used police vehicle.
