...Your detector may not seem to have good sensitivity...

Here is an excellent example:

Going along on my merry way, thinking how my travels seem always so quiet, I am approaching an overpass, and lo and behold there sits a trooper in the median camouflaged by the contrast of the shade on his black and tan crown vic from the overpass. He was sitting in perfect position monitoring the traffic approaching towards us. He was parked 45* facing forward. I was dissapointed that I had no alert, but I have seen the majority of local troopers with there radar off. So just as that thought crosses my mind, I immediately get a Ka alert (2-5 sec after me visually spotting the trooper approx 500 feet). As I approach, I scrutinize the rear deck for any antenna, nothing, and as I pass I look on the dash, and there it was, a little Ka antenna. The arrows flipped to the rear and naturally held onto the signal a little ways after, further than on my approach, but that is only natural given the circumstance.

Location is northbound turnpike and I75 overpass.

Later down the road I came upon a trooper whom had been asisting a motocycle, of particular interest was that the trooper from a full stop on the shoulder of the road just simply jumped out into traffic without regard for immediate approaching traffic, we all had to quickly adjust. What an A hole. Anyways I noted the dual Ka setup (again tell tell small antenna), and we were traveling well. He then decided to pull over at a turn around in the concrete median. He was obviously getting ready to setup shop. So I continue down my ways when all of a sudden I get a full Ka C/O blast to the rear approx 1 mile . I just though it was halarious.

Location was northbound Turnpike and south of I595. I have pointed out this location to be a constant hot spot for enforcement. It was approx 3pm.