1. You need a random car and a dead body with a backpack near this car.
2. Open the ground inventory (make sure, that you are able to move things from the ground directly to the car inventory)
3. Move the backpack from the ground to the car.
4. Now you can see, that the backpack is on the ground AND in the car.
5. Repeat the X times. Now X backpacks are in the car.
6. Use the following script command to get the vehicle inventory: getBackpackCargo (if I tested that correctly, only Backpacks are affected)
7. If you sell the content on a multiplayer server you are instantly rich, as the getBackpackCargo command return X backpacks -> **EXPLOIT**
Old Video to show the steps to reproduce this Exploit: https://www.youtube.com/watch?v=9LvyoP5vfWU
New Video including the script command (24.06.2016 - Tanoa RC Branch): https://www.youtube.com/watch?v=ebeQJiLrh4E