The Delorme PN-40 is the closest thing I have found. It will do turn by turn auto nav, just not the way you would be used to with a regular car unit. It has a beep instead of a voice to warn you of upcoming turns. It is a little cumbersome to find the POI's and set it to the routing function and it does not auto reroute if you miss a turn, you have to hit a couple keys to reroute. Maybe there is a setting to make it do this automatically, if there is I haven't found it yet. It's a pain in the dark because you have to use buttons instead of a touch screen and they are not illuminated. Like I said it will do it, but. As you can imagine it is incredible for Topo and Aerial imagery and you can buy unlimited map and imagery downloads for $29.95 for a year. I have searched long and hard for a do-it-all unit and even tried the Lowrance Crossover, but the Delorme is the closest thing I have found. I ended up buying a cheapo Garmin 207W on sale to supplement the Delorme in the vehicle.