![Smile :)](./images/smilies/original.gif)
Thanks to all the great info on this forum and other Z-specialized forums I could diagnose the cause of the issues and solve two of them:
1/ Previous owner replaced both tail lights just before selling the car, but wasn't aware about the missing third bolt on new tail lights. Easy fix.
2/ The top seal with the two torx screws on each side was leaking. Not so easy to fix but seal is waterproof now.
I did a waterproof test today by pouring some liters of water on the rear window, even with the boot lid opened and all is well. Then I closed the boot lid and poured again lots of water all over the back of the car. Still good. Except for the two boot vents that make me worry a bit. After today's water test I noticed tiny drops of water that seem to enter at least one of the vents. Couldn't check the other one as it's hidden by the foam box with all kinds off electronics in it.
Now my big question is: is it normal to have even the least amount of water noticable in the vents from the inside of the boot? Or should they be 100% dry at the inside? I'm afraid that the amount of water leaking through the vent flaps increases the longer the car may sit in the rain.
Since it's a 2011 car, I presume it has the revised vents already from the factory. Please see picture to see what I mean.
Red arrows: tiny droplets of water that entered after today's water test.
Blue arrow: probably dried up water from before