 the answer to your problems!
hey, i was googling randomly and came across your woes... i have a '52 1.8 ghia and have had the same problem you all were talking about.
the thing that is causing it is the pollen filter. basically, the seal on the pollen filter cover has always been poor due to a manufacturers defect. i used to have literally a pond in my passenger footwell after it rained. because the seal on the pollen filter cover was not tight, water leaked into the pollen filter and ran down into the footwell via the air ducts. to rectify the problem, my local garage ordered a modified pollen filter cover and ive not had a relapse since. i believe ford are aware of this defect and hence have made a modified cover. ask your local dealer about it. i can guarantee this will sort your problem out! it cost me £70 to change.. but tbh if u can find the part urself, u can DIY it with a haynes book!
hope this helps,
matt | 
