GPS routing site.

A cycling friend of mine suggested a website. No, no...another kind of website! :nonod:

Ride with GPS

Although it's aimed at bike riders, it is also useful for planning MG routes.
You can click along routes and it not only gives you driving/riding directions, you also get a profile of the altitude and steepness of the elevation. You can download the routes to a Garmin satnav from the site, but I expect you'll be able to find a website that will convert this to your own particular satnav format.:shrug:
I've just spent an entertaining 15 minutes navigating the Stelvio Pass, in Italy. :thumbsup:
Give it a try, and see what you think. You need to register, but it's free. If you are on facebook it can register you through that.