In the Suburbs head up to the Ferris wheel. (say you are facing the Ferris wheel head on from the front) drive off to the left, you'll run over trailers and see a hill in front of you and a gas can on the hill aim for this and launch off of that hill. Try to land on the first building in front of you. If you land just right you could break open the roof and fall in but if not you should be able to use the gas can to blow open the top right hand corner (that direction is based on you looking at the building while on route to it off the hill) it should blow a hole thru the roof....drop down in there and shoot the panel to lower Warthog (formerly called White Knight).
