Over the past several months I have noticed that my vehicle location on the map starts to wander where the car will still track movement but will not be on correct spot on the road.  I have adjusted the vehicle location but that appears to be a temporary fix.  I reset everything in settings where the nav will require a certain amount of driving to recalibarate itself and then everything is fine for a few days, then the wandering gradually begins again.  Any ideas what the problem could be?  If the antenna was bad wouldn’t the nav not find my location at all?  Any help would be appreciated!

Your antenna is probably going bad.  Had the same issue on the Alpine IVA-D310 that is in my Matrix.  Replace it for around $12 and you will see a world of difference.

Just ordered one, worth a shot.  Thanks!