Do any built-in Sat Navs...

[nubbin.]

...allow for route planning like TomTom and Garmin, or is it always point-to-point? TomTom's itinerary function is great to plan a custom route, so can it be done on DVD based systems?

[Oystercatcher]

Never having used a Tom Tom or Garmin, I'm guessing you mean an A-B, B-C, C-D etc. jouney? If that's right, then Honda's does.

You can create a "Today's Destinations" list which contains up to 5 destinations. When you reach each one, it drops off the list and routes you to the next. Despite it's name, it doesn't forget them at the end of the day

Or you can add "waypoints" and route via them....

Alan