[steamship]

Based on what you've said, it sounds like the drains in the plenum chamber are clogged, and the resulting downpour has filled it, with the water overflowing into the car.

Have you ever cleared them before, and have you sealed up Botang's Hole, as I suspect that to be the culprit, with the water coming in the passenger side. Can only suggest you drain off any excess water in the plenum chamber, sort out the drains, remove the carpets in the passenger footwell, as with the rubber backing, they can hold a lot of water.

I'd then suggest something like a dehumidifier in the car if you had one, or maybe just a hairdryer on the wetter areas. Check out the fuse and relay panel while you're down there and dry up as much moisture as possible.

Final thing I would check is the ECU box in the plenum chamber. Open it up and see if there is any water or moisture in it.