Water in the footwell

it is best not to waste time and turn to professionals in this field

If it is inside the car in one footwell it will be one of three things. It will be either a leaking pipe to the rear windscreen washer jet, a worn door seal rubber or the heater matrix behind the dashboard.
Get into that footwell and using the back of your hand start at the floor and feel the carpet for wetness. Work your way up the carpet towards the underside of the dashboard. Your looking for the point where the carpet goes dry. Try this near the centre of the car and nearest the door. Floor only suggests washer pipe. Wet around the door is possibly a door rubber and high under the dash is most likely the heater matrix. This may seem an odd question but does the wetness have a smell? A rotten egg smell suggests screenwash. A sweet smell could be coolant.

hi all have an audi a4 convertible 06 plate just cleaned it only to find wet carpet drivers side bulled back carpet and found about an inch of water heeelllppp

there is either a torn vapor barrier on the passenger door or the sunroof drains are blocked

the water can travel along surfaces or beams in the car so you cannot tell where it is actually leaking. in my ford windstar water leaked in right over the fuse box. it ran along a cross beam from the passenger side. if it has those plastic strips they use to go in between small gaps in the metal... like along the roof where the roof is and the metal of the sides joins it is likely they are leaking. best to take a garden hose and have someone inside the car with a flashlight on the floor looking for leaks

Your car probably has AC so the box under the hood has a drain for removed moisture and this can often clog with environmental debris; when that happens, the water can't drain any more and may end up inside the car.

the ECU is located on the passenger side floorboard underneath the consold and carpet

reset you computer, do this by removing the positive battery cable for 10 mins.

does the footwell of passenger side get wet? the hose disconnects under the carpet there, pull carpet up and simple to fix, if not then hose will have disconnected in ducting on right near back of the engine.