I bought extension mirrors for my Ram. While it did not help me see what was behind the trailer, it does allow me to see the entire lane next to me (all the way back) instead of just a small portion of the lane that my regular mirrors do. I've found it helps me anticipate what coming up and passing, as well as when I'm changing lanes. I bought the ones that clip / screw / fasten on my mirrors so that I can take them off when I'm not towing.