Vehicle Jacks no longer exist in Apocalypse Rising.
A Vehicle Jack was a rare, useful utility that can be used to flip over capsized Vehicles. The Vehicle Jack was removed on 12/6/2014 because the update flipped cars on their own , and now is no longer in the game.
Vehicle Jacks were usually found in sheds, vehicles could be flipped by selecting "interact" and clicking the upside down vehicle. Most of the times, a vehicle flips from a physics bug while another player is driving it. Vehicles stuck into the ground usually cannot be flipped with the Vehicle Jack, unless they glitch again through the ground.
It looks like a real life vehicle jack.