Also, by the time you put a MDT (mobile data terminal), multi-level filing system to hold the myriad paperwork that all police agencies must file, and a center-console gear shift, you have very little room left over for actual people. The old Ford Crown Vic PI (police interceptor) had a shift on the column, as does the Tahoe, allowing for extra room.
As for mileage, almost all police vehicles have supercharged V8s, meaning none get good mileage. SUVs are also more durable than sedans.
Back to the room factor, there is very little backseat room even in an SUV designed for police work because the cockpit is basically a secure box. Since not all officers are the same size, you have to adopt a "one size fits all" approach and take up room in the backseat. They don't take up room in the cargo portion because officers have gear bags, flares, and other items in the back. End result? They don't make a sedan even close to what the PI once offered, so you'll see more and more agencies go to the SUV.
As for the cost? That lies with Transportation Services because they lease all those vehicles back to UPD.
Rod, you and I agree on most all things, especially for two people who -- to my knowledge -- couldn't pick each other out of a lineup. I think you're barking up the wrong tree here and are trying a little to hard to poke another poster with a stick.