During the early days of the Milhous Nixon Memorial Double Nickel Speed Limit, some highway patrolmen would park on top of an overpass, listening on their own CB until they heard the "smokey reports" warning everybody where they were. Then they'd move on down to another overpass and repeat. Properly executed, this allowed one officer to seem to be in three different places at once, slowing down traffic on a long stretch of highway to the legal limit.
The point of this is, being conspicuous and actively seeking to publicize their whereabouts via the truckers' grapevine was a very effective way to get people driving at safe, legal speeds. The ones who hide out trying to write as many tickets as possible are less effective at slowing traffic--but more effective at generating revenue from traffic fines.
If the object is traffic safety, let them flash the lights. And trade in the plain-white unmarked cars for a black-and-white cruiser with big reflective "Highway Patrol" decals on every side, and a big light bar on the roof. But if the goal is just to collect fines, they'll keep the enforcement out of sight.
