We went to the Boat, Sport, and Travel show today and I stumbled across this baby. It's built on a 2007 GMC Yukon and will supposedly survive an encounter with EF4 and EF5 tornadoes. All windows are double-paned, with the outside panes at 1/2". The front windshield still has the stock wiper blades behind the outer pane, just in case of a leak.