Guys, the smell i believe is mould forming in the aircon system due to the humid condiditons, i happened upon the last can of a "new" product on the shelves of tesco. it was this stuff http://www.netparts.co.uk/store/index.php?main_page=product_info&products_id=92. I read the label a good few times and then decided (after making sure i had the box and receipt and was set up to sue if it went wrong) i would go ahead with it. and it worked! really well! its an aerosol can that locks on when you press it, you sit it down in the car with the air con on full and interior circulation. closs dorrs n windows and leave for 10 mins then go back with a towel handy to wipe the excess away and hey presto! the smell at first is a bit funky but goes away within the day. hope this helps
oh and yeah, i panicked when i saw that puddle but fortunately i had just parked next to antoher z and he had a matching puddle so i figured it out