Considering my leaf rig is used constantly late October through first part of February. So 4 full months of the year plus some. February still busy but slows down. $400 is worth it if it helps guide me (and more importantly my other driver into the parking space easier and quicker and make be avoid a backup accident it's well worth it in my opinion). NT has been good to me when a few things I bought were crap I took them right back no questions.