Water leak in drivers footwell?

I also have the same problem with water leaking in the drivers footwell. I have a 54 corsa. I have now been to 3 garages who have taken carpets and seat out and sat in it with someone spraying a hose pipe on it and none of the garages could find where it is leaking in. They all said it was a fiddly job to do so to be honest i don't think they could be bothered. It is now booked in at a 4th garage next month wish me luck cannot cope with another winter of frozen windows inside as well as out