Mathgod

(Accidentally posted in a similar CLS thread after doing some research)
I am 2 days into ownership of my 2017 AMG GTS. After a 1,000 mile drive back home, I ran it through a touchless car wash and noticed the trunk was completely wet. It has a GTR (?) wing on it, and upon closer inspection I am not sure the drains are functioning. The passenger side drain goes nowhere and the drivers side is plugged. The center line may be connected but I can't follow it all of the way to the center connection behind the latch. Drivers side drain felt was soaked as well. Any advice is greatly appreciated!! Glad to be a part of the AMG family!

Passenger side (pulled out on purpose)

Driver side

Mathgod

After doing more research and looking at my pics, I'm guessing the weather seal at the wing base is shot (I'll do a water test to verify). Plus it looks like the previous owner did a hack job with caulk to seal it.

G. P

There is a water drain entry point right at the center of the spoiler base on the side closer to the rear of the car. If it's not plugged shut, water will get into this drain hole and escape through the 2 pipes that you referred to and driver and passenger side. You can try to block both pipes from under the trunk and see if it works, but water in the drainpipe may eventually drip into the track anyhow. If you happen to remove the base plate (the one that holds the wing), use butyl sealant tape ( ) rolled into thin pipe shape and run it into the channel that is built into the underside of the base plate (as design by the mfc). You will be able to get rid of all this foam.

G. P

Use this YouTube video to guide you through the uninstall/install process:

dlefty

Based on the horrible sloppiness of the grey goop they used as a seal attempt, I’m sure the rest of the installation is just as “great”, might be worth staring all over, making sure to properly connect all drainage, lines, plugs, seals, etc.
A couple years back two GTS’ came to me to help them resolve leaky aftermarket wing issues, I started all over with install, seals, drainage tubes, plugs, a little custom tweaking and then it was fine.

ZephyrAMG

Did they not spray it with paint all the way? That trunk needs some TLC

Skilly

unless you have a drain going into the trunk it is 100% the 0-ring seal at the base of the wing. Its not seated properly and its letting water in - once they are damaged you cant fix it with the caulking that the previous owner did - youll be chasing the issue forever. Take it all apart and clean all of that junk away. Make sure the surface is squeaky clean. Get a new o-ring and start over.

When you reinstall the base, its about 12 bolts. alternate tightening and don't fully tighten any one area at a time - coordination and spreading the torquing down across the panel will stop you from pinching or flattening the o-ring and having to do it all over again.

Mathgod

Quick update and follow up question. I sealed the rear gap on the outside of the spoiler / trunk lid (front gap was already sealed) along with plugging the loose drain pipes that were no longer connected. Took my chances and went thru the touchless car wash and the trunk was dry.

However, today I am now getting the rear spoiler inoperative warning. Is the light blue plug in my original pic above a spoiler dealer module?
Thanks!

G. P

yes, this is the spoiler delete module. Make sure the contacts are clean, no damage from the water you had there before and it is plugged all the way in.