Use Mapsource software and the Metroguide Europe CD v 6.0. This gives street level detail and the Mapsource software for the PC allows you to route plan and then transfer routes and waypoints to the 176c. You'll also need a programmable chip and USB programmer.
I used the American version in the US and it was very useful. It does not give a commentary, for that you need the new 276c, but I found it very useful when visiting new places. I was given Metroguide Europe as a birthday present although still waiting to use it in anger.