There was a funny story told to me by a border guard on that border stop, it seemed a big American car was stopped a few months earlier with three guys in it, who were acting quite suspicious, not very co-operative at all.
Very reluctant to allow the boot to be opened, a guard insisted on having the boot opened, the drive finally released the boot lid, and the office lifted the lid, as he lifted it up there was a forth guy in it, who popped up and yelled "I'm a fruit fly", the guard got such a fright he jumped back slamming the lid down as he did.
The guy in the boot had to be taken to the local hospital for concussion.
Moral of the story, Don't Mess with the border guards.π€£