Right all sorted (I think).
Sunroof does indeed have 2 rear drain pipes but contrary to the Bentley manual then don’t exit down by rhe rear bumper and don’t go down the D pillar.
They actually go down inside the C pillar. You’ll only be able to see the very top as the rest is pretty much hidden. They also exit at the top of the rear wheel arches.
Here’s what I found on mine.
If you have any damp patches at the rear pillars then it’s most likely the rear drains are blocked. Water fills up the pipes and overflows out the channel onto the inside of the headliner. The headliner is pretty substantial and although not waterproof the water seems to flow to the lowest point. As my car is always parked front higher it flows backwards.
At first glance thought I might need to completely remove the headliner. Glad I didn’t though. The rear drains are pretty far back and you can’t see them through the gap when the sunroof is open
Thinking that my drains might have popped off I decided to lower the rear half of the headliner to get a cleared view.
To do this you need to remove 5 bits of interior trim. Both D pillars first. Then the rearmost trim above the boot. Then the two bits of trim over the back doors. These are all kept in with a combination of screws and clips - some pretty well hidden. They are plastic though so don’t bend them too much.
With all the removed you can pull out the boot light too and pull the headliner down slightly. This is what you’ll see.
- View from boot
The circled bits are the two rear drains.
- Rear drain location
As you can see the pipes disappear behind the airbags and down the C pillar. I decided to disconnect them here and run a pipe cleaner down them. After doing that water came gushing out the wheel well (from all over the place) so I must have got rid of the blockage. I tried it a few times and also ran some compressed air down. I still couldn’t locate exactly where the exit was though and the pipe cleaner had an abrupt stop about two foot down the pipe. One the joins at the drain had a teenie tiny drip so I sealed both of them with some heat shrink too.
- Drain with better seal
Now to find the exit. With the wheel removed I then got rid of the wheel arch liner. Still not 100% obvious (like the front ones which exit in a nice green pipe down the a pillar). Removed this bracket and the grommet is behind it. Think this is the TPMS receiver so there’s one on each side.
- TPMS receiver and grommet behind
With this removed this is what you see.
- Rear drain exit
So there you have it. Seems to drain really nice now. Ready for a storm tonight so will check tomorrow if it can cope with the rain.
Here’s some more photos with the trim removed incase anyone has issues with airbags etc. I also found a random wire going round my boot trim. Traced back and it goes to the loom?? One wheel arch also had a false widow spider in it
I should also add that I have a solar sunroof but the normal
Sunroof isn’t much different.
If you want to clean the rear drains I’d suggest removing the rear wheel arch liners and cleaning the gromit first. Mine didn’t have any gunk at the sunroof bit but looks like the gromit is easily squashed and blocked.
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