The seal is before or ahead of those holes. What little fume that enter those holes should be captured inside the lid.
What do you have for interior panel ?
The trunk has large factory holes made into the interior of the trunk lid. The trunk lid is totally porous when it come to air. There is also a hinged panel between the trunk area and the passenger compartment but exhaust fumes and air can pass through numerous openings between the body panels. I'll show this in the pics that I'll take. I went outside a few minutes ago to take some pics but the battery in the camera was dead so I'm charging it while I write.