Avtex do a range of satellite navigation (Sat Navs) for Motorhomes / Caravans usage.
They have collaborated with Caravan And Motorhome Club and Garmin to bring you a sat nav which allows you to enter in dimensions of your Motorhome or Towed Caravan + car to allow easy, safe trips and with the added benefit of Points Of Interest (POIs) of Campsites making it childs play to find a campsite and navigate to it.