Z refers to a multi-type door structure inside the door impact beam, due to the design structure like a letter ldquo; Zrdquo; named type, purpose of this design is the impact from below in order to better the side. Z-doors in general appear more upscale models, such as Audi, Aston Martin and other brands, but currently there are an increasing number of joint venture vehicle, autonomous vehicles are also beginning to use the Z-type doors, such as Citroen.
