Certification.

The vehicle is officially certified as a complete unit. The BMW X5 Security Plus is subjected to tests which involve hundreds of rounds being fired at the finished vehicle, to ensure protection against fire from automatic weapons like the AK-47. This official certification is only given where the complete vehicle - and not just the materials used in it - has successfully stood up to the necessary ballistic tests. The armoured underbody can protect against the simultaneous detonation of two DM51 hand grenades.