Meaning of the word "shutface"

I have a question concerning the location of the vehicle safety certification label in a certain car. The corresponding user's manual says: "A vehicle safety certification label is attached to the rear shutface of the driver' s door".

I am not a native speaker of English and hence my question - what is the rear shutface, exactly. Is this a part of the door or the body of the car (i.e. the B pillar). If this is affixed to the doors then where exactly - in plain English? Is this the part of the doors that is "hidden" when the doors are closed - i.e. the width of the doors?

Solution 1:

It's a domain-specific "neologism" (probably not widely used even there, and possibly a complete "one-off" in the context you found).

It means the flat part of the door between the inner and outer faces, opposite the hinge side (i.e. - the bit you can only see when the car door is open).

In practice, such stickers may also be positioned on the car body rather than the door itself (lining up with the hinge side of the door, as in the second picture). Since the usage is a neologism, I see no reason to suppose "shutface" specifically and only means the one on the door. So it really just means a facing edge which isn't visible when the door is closed.