Well, let's see here, take the average cop...
Drives a good 50 miles to find the perfect donut shop...
Grabs a dozen donuts and a cup of coffee, which of course are state paid
Then drives let's say 20-30 miles to find a good speed clocking spot....
Get's in his donut friendly position, and turns his speed gun on...
Eats a few donuts and drinks some coffee, then this hot m3 blazes by, radar goes crazy, cop jumps up, drops his coffee and a few donuts, by the time he gets to leaving his spot, he's got a huge mess in the car and the M3 is loooooong gone...
So, now he has to take his car to get detailed and cleaned up, and of course tax paid...
Then buy more donuts and coffee, which god forbid they can't run without.... and eventually by the end of the day he might be able to stop someone doing like 6 over