Clamshell not Flush w/Body when Top is Down

[Cbonilla]

Went out to my Boxster yesterday and, wouldn't you know it, when I put the top down the clamshell was once again flush with the trunk. So I had to delay investigating the problem

But last night I had a thought. Referring to the guide you included (3. The nut and slotted screw...) could it be that the locking nut isn't tightened down and sometimes it finds a position where the clamshell sits just right and sometimes doesn't? Thoughts?

Carlos