Have a look at "Waze". Its a free app that uses fellow users to determine road congestion. I use it here (Germany) and in France. It works well.
Used it yesterday in Paris (not in a Morgan) and performed very well, reminded me of the mini bus working its way through Turin in the Italian Job.
Works equally well in the Morgan, where i connect the iPhone by USB to the radio. Turn instruction then get broadcast via the car speakers.
