Il have the door card back off and have a check at my handy work again. Could also be something to do with the pollen filter, they have a nasty habit of leaking through the housing and having replaced it recently I could have refitted it wrong although I cant see how it could leak from the bulkhead, miss the front and then just settle in the back.
Il have a looksy at your suggestion spook, once I can find someone to drive me around for a bit xx
UPDATE
think I may have found the culprit, fron door seals, think its filling up the doors and the seals gone at the back, which leads to the rear kickwells x