This is a classic glitch! Back in Mexico what we used to do was a dp LP right in the hole of the broken window (Ryu/Ken should be standing up right in front of the window, not in the ground), but the positioning was more accurate in the left side.error1 wrote:Car Float Glitch
In Street Fighter II if you break one side of the car so that it causes red hit sparks and then do a backwards jump and attack, it may cause your character to become stuck in mid air. To jump backwards you need to press up and back at the same time, it's harder then it sounds. The easiest normals to get it to work with are Ryu and Ken's HK, and E. Honda's MK. The spot you need to hit to trigger the glitch is very small so expect for it to take you a ton of tries. A second player can knock you out of it, but if time runs out with you stuck then the game is effectively frozen.
Video Example: http://www.filefront.com/17283624/sf2car%20bonus.mkv
I see there were other options to do.