Pity the Poor Reality
CSI Miami, at least on the TV show, has silver Hummers. Because they're cool. Because they consume enough gas to make oil companies want to sponsor the show? Who knows. They all drive these huge guzzlers. But they have good excuses: they need to store a lot of forensic equipment in the back, and occasionally, on at least one episode, they have to go off-road.
But Austin, a poor little town in the real world, has a mere Ford Windstar van that says
on the back. That's us, the Aw-Shucks Police Department. Low budget, un-flashy. Presumably effective even if they don't have a contract with CBS.