so long story short, i had to change my tire with the spare yesterday. as i took out the spare, i noticed that there was literally a small puddle of water in the spare tire well! i have NO idea how it got in there; the carpet was not damp, my trunk tray did not collect any water or showed any signs of moisture. i'm befuddled as to where the water came from. it did rain for a few days but... there shouldn't be any water in the car! unless that's a feature?

any ideas?

 

I've heard this before, but a long time ago. If I recall correctly, moisture could get in through the sunroof (if the seals are worn or sunroof open while raining), and typically evacuates/drains inside through 3 places - through A(2) and C(1) pillars. There are drainage tubes between the roof and roof lining. If the C pillar drainage tube is clogged, then the moisture would leak into the trunk.
Again, I could be way off here, but it's an "idea".

 

that's interesting... but i didn't have my moonroof open or vented... i'll have to call my service advisor and see what's up...

 

I read in one of the tech bulletins that if a factory spoiler isn't installed correctly on the trunk lid it can cause leaking into the trunk. do you have a spoiler?

 

I just brought my TL in today for the same problem and the dealer had previously installed the lip spoiler. Did the dealer fix your problem? The service writer told me it was the spoiler and they would have to remove and reinstall it.

 

is the trunk seal ok? check the rear drain tubes

 

hrm... my service advisor never returned my call... but i don't have an OEM trunk spoiler; just the M3-style spoiler with 3m tape... trunk seals *look* ok... again, carpet and rest of trunk was bone dry. only the well with the spare tire had water...