Allan,
I have the same unit in my other car and it works this way. I am in Atlanta and laser is pretty common now. As you probably know with laser, when the normal detector goes off you already have a ticket. The SRX system from passport jams the laser signal so the officer never gets a reading. (The SRX sytem is considered to be about 96% effective.) There is a button in the car that you have to push to release the jamming process. (BTW..Escort calls it "Shifting" vs Jamming). Once you press the button twice, it stops the jamming process and they can get a speed on you. Some basic info...laser must be stationary to be used, max range is 1000 feet, typical range is usually around 500 feet. Laser is a more pinpoint beam than radar, they actually look through a sight at your car and point to a specific spot on the car. From the front that is usually the license plate or if no plate on front they aim at your headlights. From the back it is the license plate. Because it is more of a pinpoint beam you typically will not be able to pick up a signal when they are shooting someone else, unlike radar which sends out a wider beam and "splatters" therefore giving radar detectors in the area a chance to pick up the signal.
So having said all of that, which I got from reading the radar sites and passport, I have used my other one for two years and it has saved me about 10 times. I originally thought that when they could not get a reading and they could see you, they would stop you anyway just to hassle you. They have not done that so far with me, they just shoot and move on to the next car. My other car is a turbo porsche, so it would be a good target, but they just move on to the next car. My speeds have typically been 20 over the limit when they shot at me. If it was way over they might just chase you down anyway. Hope that helps, let me know what else I can provide.
Don
