I bought a radar detector from my local car audio shop a while back and he said that if it goes off and your speeding its usaually too late because when it goes off it means that your in there range of radar. He said that if your traveling behind someone thats going as fast as you then you might not get caught because they will radar them. I just don't understand the usefullness of a radar detector if it beeps when your in the cops range, because then they can ticket you. I'm really starting to doubt whether this guy knows what he is talking about. Can anybody clear this up for me? Or just explain the function of a radar detector