To perform this, simply ram into a car that is at it's most vulnerable position, upside down. Continue to hit it, and if fast enough, the Bad Landing notice will not appear, leaving the car in a defenseless position, It's better if you hit your target into the wall. Combining this with King's Rampage or Juggle can yield enormous amounts of damage even before they can return to normal and continue driving off. Be careful that you will usually glitch through EL KING when he lands upside down.
Note that this will be rare among other Players, as they are skilled enough to not land badly.