Pick up any car and get it on top of a set of rocks or high building. You can do this by jumping with it or throwing it from higher ledges. When the desired height is reached, just get into the car and the achievement is yours.
Go to the Central Point building in Shai-Gen where Cowell is located, then jump into any car and find your way up the staircase to the front door of the building. Kill all Shai-gen in the bottom floor of the building if you have yet to take out Cowell, then drive across the room to the elevator. Jump out and open the lift's doors. Drive into the elevator and turn on the lift. Jump into your car. About halfway up the lift you will gain the achievement. This will work for any vehicle and you don't have to defeat Cowell.
-Make your way to the supply point on the map called "Garcia Point"; the second north-most supply point in the Los Muertos section of Pacific City. Exit that supply point (or make your way there if you have not already secured that supply point) and jump up onto the plateau just above the shack. Once there, you should see a jeep. Get into the jeep and drive forward about a car length and drive your front wheels up on a rock.