UK Car Repair: passenger floor wet in vauxhall vectra, rain water, drain hose

Question
hi i have got a 54 plate vauxhall vectra and there are no problems with anything i can see but the floor on the passenger front side of the car is soaked do you know what this might be i have looked underneath and it looks wet on the bottom but thats all i can see but it is raining aswell so not sure thats what that is please can u advise me of what this might  be  

Answer
Does it have Air Conditioning?  Often, the drain hose from the evaporator behind the dash breaks, or comes off.  The water then ends up on the floor. Another possibility is rain water entering the floor from underneath.   Take out the carpets and dry them out, in the meantime you may be able to see where the source is. What is a 54 plate?