+1 on the V1. I had the pleasure of using one on a few trips and it is unbelievable! Gives you enough time to react to the signal, slow down to the appropriate speed, check traffic and merge out of the fast lane, and still have enough time to ask yourself, "Where is this guy?" only to see him standing on the median a good distance away. My opinion is, if you are a defensive driver and watch out for cops actively while you "break the law", with the V1 you will likely never get a ticket.
I am seriously considering one, but money is tight.