Dear Saxo-vtr-1994,
Thanks for your kind reply

What you may want to try is drying the footwell first, completly. and then you can dry off the outside of your car including the passenger door shut area and under the bonnet on the passenger side inner wing area and also dry off the front passenger side front windscreen area and also under the bonnet passenger side bulkhead area and also the scuttle panel area too.
Secondly, ( this is where most people go wrong, is NOT to blast the living daylights of outside of your car with a steam cleaner or a power washer. ) what you need to do is to go around the part of your car that is leaking in rainwater, with a fairy liquid bottle of water and squirt it in the places, like passenger side bulkhead area. What you need to do is start off squirting your fairy liquid bottle full of water at the lowest point on your car ( best to have someone else sitting in the car with a lead light looking for leaks ) and then once are sure that you have ruled out ALL the low, only then should you take your search higher.
Vince,