Destroyed vehicles glitch
From Halopedia, the Halo wiki
To Get inside destroyed vehicles, you will need a Spartan Laser. Then, approach near a vehicle (preferably a Warthog) and stand next to it (meaning that your body is touching the vehicle). Press R (Right Trigger) then B to enter/ride/drive on top. Next charge the Spartan Laser and just as you fired, enter the vehicle. Note that you can't drive them.
