Nissan Patrol 4x4 (Africa)

After heavy rains here in the Western Cape I noticed that the mat in the boot of my GU was very damp and the felt underneath was very wet. No windows or doors were left open and there is no obvious point of entry that I can spot where the water could come in.

I recently had a custom drawer system installed so it is almost impossible to lift the mat and easily identify where the water came in, but what I have identified is that the water is probably coming in on the left of the vehicle (when facing the boot) somewhere close to the wheel arch and I suspect it is the compartment where the rear fan intake is.

My question to the forum members is if it is possible that the water is coming in through the rear window air vents? Im sure that Nissan would have designed these vents to drain should water enter through there and maybe there is a drain that is blocked somewhere?

Im sure this wont be of any use, but, I had the same issue of dampness in that area. It was as a result of the drain pipe for the rear aircon - it and its grommet coming out the rear arch had come loose and it was dripping inside the car instead of out.
I see you say its when standing in the rain, so I guess not the same issue. But thought id mention it in case it could be as a result of driving with the ACs on before you park it.

Where does the drains for the sunroof exit? If it exits down the C pillar then that might be the cause of water in the back

Never thought of that option. I will take a closer look this weekend. Thanks

An update...

I found that the root cause of the water leak was attributed to an electrical grommet, which is fitted to my custom gull wing, that was loose and improperly sealed. This has now been resolved and all tests show that the issue is now resolved.