That V1 is too old. Buy a new V1 or look into the Passport 9500ci. Great product! Had it and was great but ordered the k40 RL360 because I got it for a good price. Getting it installed tonight but my buddys out performed my 9500ci, but not by a lot. K40 jams harder. (Jammer is an another add on option. Does not come with it). Completely concealed behind bumpers aswell as lights hidden in rear mirror via. A mount i made and has a manual shut off switch you can hide.
Don't know your price range but V1 is very reputable and so is the 9500ci. dash mounted radars will usually have much less range in the rear. V1 is great for the price and has good range in the front. Buy it and if you don't like it, return it. Best bang for your buck = V1. Best concealed for the price = k40