Leaking WD Boxer sliding door sliding window?

Hi all, just completed a trip in sunny Spain and Portugal   where we had some bad weather, well floods . Thing is we noticed water getting inside wetting the sliding door cover material at one point under the sliding doors sliding window which was closed against its seals. 
So when we got a break in the thunder and lightening I slid the window open to find the bottom of the rubber seal groove full of water.
I wondered if there is a drain hole at one corner point but failed to clear what looked like one.

Does anyone know if there is a drain hole and is it possible to clear it and where does the water drain too?

We spent an interesting night on an Aire surrounded by and listening to gurgling water in gullies, water bursting from man hole covers and a river that had burst it's banks flooding the grey waste drain grid. The Sat Nav tried to send us over a bridge that was underwater judging from the still visible hand rails!! 

We have a 06 Symbol so it could be different but our window frame has milled slots at the forward and aft bottom corners for drainage. It would be hard to miss them, but I have had to clear muck out of them.

Paul 300358 wrote:We have a 06 Symbol so it could be different but our window frame has milled slots at the forward and aft bottom corners for drainage. It would be hard to miss them, but I have had to clear muck out of them.

Ditto to that. I clear out the slots (which you can't see when they are full of water) with the pointy end of a nylon zip tie. They drain down a flat profile pipe under the frame running down the inside of the door. Funny it only seems to be the door window that gets blocked

I had exactly the same problem not so long back in my Warwick XL. If you look under the window on the outside - it overlaps the bodywork, mine had a bit of grit stuck in one of the drain holes. I scraped it out with a knitting needle.

Zip tie and Knitting needle, essential parts of any emergency kit

Paul 300358 wrote:Zip tie and Knitting needle, essential parts of any emergency kit

Don't forget Gaffa Tape 

Better known as Star Wars Tape.    

Why?

Because it has a light side and a dark side and it binds the universe together 

Thanks for your excellent replies. 

The leaking happened during torrential rain in eastern Portugal and at night (when I took a look) so I had a quick look and tried to clean the glass in the hope of a better seal.
As you say its impossible to see any drain hole when wet.

So armed with your information  I had a good look today and sure enough in the sliding window plastic frame groove there is a rectangular hole, in fact two holes one at each end. I poked around with a screw driver but failed to find a drain hole. Then I bent some wire at 90 degrees and hey presto a drain slot was discovered to the outside of the frame. It seemed impossible to thread the wire in and through and so have had to hope my clearing out of the holes on both sides will be sufficient.
I've also noticed that the glass surface becomes dirty and cruddy  along its bottom edge only so I've cleaned that away with a nylon scourer. I've also cleaned any crud off the rubber seal, again along the bottom edge strip.

Hopefully that will solve the problem but tomorrow I'll try and pour some water in and see if it drains away.

I think due to dirt and crud the seals were not sealing against the glass so allowing water to pass.

Thanks again.