I've just repaired my rear wash pipe as mentioned by Typecastboy.
From my experience I would suggest:-
1:- Try removing the Front door bottom trim first. If the leak is not in that area move on to the rear panel. I removed the rear seats and rear panel first and the leak was not in that area. Sods law which ever you do first the chance its in the other area but the door trim can be removed in a few minutes.
2:- With the trim removed and the Rear wash wipe pump activated the liquid came out like a water pistol through a pin hole in the pipe.
3:- I cut the pipe through the hole and used an "In - Line connector" from Halfords £1.60(Code HFX231) applied a bit of silicone grease because it was tight - job done (no extra pipe required).
I did try some connectors from a pet shop - aquarium tube connectors (20p each) but these did not work.