Metal Gear Solid: Peace Walker Tips

Capture a Vehicle
With any vehicle (not an AI), there will usually be a squadron of soldiers supporting it. You have to eliminate all the soldiers, either lethally or non-lethally. When the first squad is gone, soon enough backup will arrive. Keep eliminating soldiers until no more seem to arrive within a 20 or so seconds. If you've happened to keep under the radar this entire time without an Alert, the Captain controlling the vehicle will pop his head out.

If you have been spotted, you need to weaken the vehicle by 3 bars of health. After that, you can simply take out the Captain any way you wish. You will then capture the vehicle. Further into the game, more difficult vehicles must be depleted by a minimum of four bars of health before capture is possible instead of three like earlier ones.