Common problem on the Corsa passenger side. I have a Corsa 'C' 2004. I removed the interior trim panels, passenger seat and lifted the soaking carpet as much as possible. The sound deading mats against the bulkhead under the carpet are impossible to remove without vast disassembly of the dash structures so I just prised these up as much as possible and squeezed out as much water as possible. I used a VAX to suck as much water as possible out of the car. Spent the next day drying it out in a garage with a fan heater. All this I did after stuffing paper tissue tell tales up around the heater, EBM module clearing the drain holes under the scuttle panel etc etc all the usual stuff you can read about in similar help sites, but to no result. Anyway once thoughly dry, move the car outside and either dust the inside floor pan with talc or stick lots of paper issues across the floor and sill sides with small bits of sticky tape. Turn on the hosepipe aiming the water flow at the top central edge of the windscreen. Give it plenty and soak for say 30 minutes. Check the talc or telltales for water. Note the highest point. It is this area to home in on. Dry it up and re talc in that area and turn on the hose again immediately above as and as close as possible to that point. Repeat mainly by moving the hose lower and lower until no water gets in. You should have a pretty narrow area by now. Mine turned out to be getting into the car through the sill box section joints just by the side of the passenger seat when water was poured into the gap between the front wing and the front door post. I have yet to get behind the wing to seal it up, but I know where the problem is - 90% of the job done.
CORSA C mechanic, February 2010
