I did some research into detectors a couple years ago. What I gathered is: If the patrolman is driving around with his radar on, most units will pick it up. If the patrolman is stationary with his laser sighted in on you, he's probably going to get a reading. If your laser detector picks up the signal, then the officer has likely received his signal also. Also, that laser signal is 3' wide at a distance of 1000'. The officer is likely aiming at your license plate and a detector hanging from your rearview mirror isn't even going to see the signal.
I suppose that the alleged "jammers" may be effective, but who knows.
Save the speed for the track. Besides, anybody can go fast in a straight line.