I was looking at UniSolar 128 watt flexible solar panels which are 18ft by 1.5ft. It seems many vehicle roofs are not 18ft long. They do make 68 watt panels that are 10ft by 1.5ft. <br><br>I just happen to see that Xunlight has 100 watt flexible panels (XR12) that are 5'11" by 2'11" and weigh 9 lbs each. It seems like better dimensions for a van roof.<br><br>It does seem that they are more expensive than UniSolar per watt.<br><br>http://www.xunlight.com/products/rooftop/<br><br>