MY BUDDY AND I both ride together all the time..( not in same car) and for clarification he has older model I forgot what model v1 BUT HE BOUGHT IN NEW IN 2004 and mine is the brand new 3.872 version. We were on cell phone talking to each other I was leading infront and he was behind me, traveling on a winding up and down hilly lakeside road when I recieved a quick ka high alert then went away..30 seconds later another hit so I figured it was instant On I was recieving rear signal. I told my friend to slow over phone and we must have been hit 4 more times on and off and finally in rear view mirror state trooper was following. I did not site the trooper in my mirrors for over 5 minutes untill he was right on us, My v1 was alerting at the beginning of the 5 minutes. His V1 did not alert untill trooper was in plain sight and then it went on once when trooper was right behind him. Just a fair warning to who have older versions yes it is still a v1 and great ! But there are upgrades that make it even better now invest and upgrade, ITS WORTH IT!!