I bought the Magellian RoadMate RV9165T-LM from Camping world (very expensive). Unfortunately it does not work as advertised. I have loaded the truck/rig data in order to avoid places I can't go, but it doesn't do any good. Several times I have had to over ride it and change the route. I have learned to pre-plan each trip with google earth/maps to make sure there are no places which would put me in a bind. I have reloaded the SW and Maps several times hoping it would help, but no so. I find that the Iphone does just as good and the maps are more up to date. In addition to the routing problems it also has a awakward power connection which comes off and it takes a very long to to route and reroute.