Killed Vehicle
From Halopedia, the Halo wiki
Killed Vehicle is a medal achieved for destroying a vehicle in Halo 3. It resembles the Stunned achievement medal. It is represented by a gray cross with a do not enter sign without text embedded in it.
This medal was found in the Halo 3 code, but was not included in the final version of gameplay, and is therefore unachievable. For this reason, the medal is believed to be a bugged medal.
