The thing about it, as I've talked to a few HP....

95% of the people they WANT to get are stopped by marked cars. If someone is moderately exceeding the limit, but driving in a safe manner, ala paying attention, then 99% of the time, they aren't going to get stopped.

Of course, this discounts the bat out of hell drivers, and the cop with a stick up his.... but honestly, the careful drivers aren't what they are looking for... Most of the time.

It just seems a waste of money for them to outfit all of these unmarked vehicles when 95% are going to get caught in an ambush or aren't paying enough attention to see a marked vehicle....

But then we ARE talking about government....