Our 09 450H is back from the dead (see brake module thread) and now my wife would rather drive it than the intended replacement. One thing we noticed on a recent 3 hour trip was the nav system seemed to be quite a bit off. It kept trying to direct me away from the road, a LONG way. For example, on one recommended turn direction, it took us to a highway intersection, turn and then continue for about 4 miles, then to perform a "Safe U-Turn", back to where we were before. The three hour trip, by the time estimate would have been close to 5 hours (140 miles). Even as we were close to our destination, it was almost an hour off. There were close to 10 turn misdirections. I have traveled that road many times and am well familiar with it. I was just using the GPS as a time guide which would have been a real cluster.

This nav system is DVD driven, so I was wondering if there were upgrades available? The dealer upgrades are a bit ridiculous IMHO.

 

You can only get the update from the dealer but I believe the map update for our GS ended in 2014 or 2015. You can get counterfeit nav disk but it's more of a headache down the road. Sometimes it won't load or the reader won't read the disk at all.

Have you checked the route setting? It may be redirecting you to some back road or something.