[Proggy]

Getting a very odd water leak into the trunk. It's right in the middle of the trunk and presents itself while parked.

It was difficult to determine where the water was coming from before disassembling the interior (it seemed to be wet in random spots, but clearly leaking a lot of water). First thing I checked were the taillight seals, both are good, no evidence of leak there.

Next I pulled out the driver's side trunk vent (behind the amplifier) and confirmed the sunroof drain on that side was working productively and wasn't blocked or disconnected upstream somewhere.

The trunk lid rubber is supple and in good condition throughout.

Most recently, I removed the rear seat so I could crawl in there and see where it's coming from with the trunk lid closed. Everything around the trunk lid is bone dry, leading me to believe the seal is good. Checked the rubber boot for the trunk wiring loom, that's fine too.

THEN BINGO!

If I stick my pinky finger in the hole pictured below, it feels wet (and shoots a mini stream of water out when I pull my finger out). There is somehow water pooling into the cavity under the parcel shelf, then dripping down on the trunk floor from above. It's probably sloshing around and coming out in random areas when driving, too, which made trying to track this down really difficult.

How is the water entering this area!? Thanks in advance for any thoughts you might have to help.

[Wolf 335]

Check your rubber wiring loom going from body to trunk lid. Water could be making its way through there.

[Proggy]

The wiring loom boot looks good (unfortunately?).

The car came to me with tinted windows, I wonder if they removed the back glass to install the tint and now there's a leak between the glass and the pinch weld. Just a thought. I welcome ANY other possible solutions!

Thanks

[Wolf 335]

Try pouring water over the rear window perimiter and observe. Most likely its the window seal.

[Serf27]

Remove the wire loom boot and make sure it’s clean and makes a good seal.
Windshield sealant may also be bad.
I think a rear sunroof drain also passes through the c pillar and might leak into that area.

[Proggy]

Thanks for everyone’s thoughts. I’ve logically narrowed it down to the back glass and have made an appointment to have it removed/resealed next week. I’ll loop back to let you know the result.

[AllBlackBimmer]

Check your tail light gaskets

[Proggy]

UPDATE: Back glass bonding had a failed spot, glass shop pulled it and resealed it. Mystery leak solved!

Originally Posted by AllBlackBimmer

Check your tail light gaskets

Originally Posted by Wolf 335

Check your rubber wiring loom going from body to trunk lid. Water could be making its way through there.

Originally Posted by Serf27

Remove the wire loom boot and make sure it’s clean and makes a good seal.
Windshield sealant may also be bad.
I think a rear sunroof drain also passes through the c pillar and might leak into that area.