Or, you can do what we do...
I outgrew S&T years ago and while it is stupid easy to download the route to the Garmin we keep on the dash, I found it to be simpler to just set the Garmin up for that day's run, or maybe even just the first stop of the day. This is easier as I have used the navigator to plan the entire excursion and that is often outside the capability of the little stand-alone GPS. Once there, clear that route and set the next. As we are travelers and not so much campers, we do a lot of avoiding well traveled roads and the Garmin just can't be made to understand that we don't want to take the big road. Besides, this doesn't require getting out any other cables and lets you see what Mr. Garmin is thinking is good.
Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything.
- Charles Kuralt
Matt