How to Fix Water Leaking into the Cabin!

[oldschool]

Perished windscreen and door rubbers are the obvious places to look first...get a friend to play the garden hose over them while you sit inside the car looking for leaks.
Another less obvious place is through the firewall via the heater pipes!
This happens when water runs down the side of the firewall bulb, out the bottom and back along the lip, before dripping onto the heater pipes, which aren't sealed in the firewall!
It then runs down inside the cabin by the pedals.
Pretty easy to fix...bend the bulb lip down so the water drips out (rather than running back) missing the heater pipes, as in the photo.
Also, make sure the (Chrysler) windscreen washer hose is above the lip as in the photo. If it's below...the water can drip onto it and then run back along it falling onto the heater pipes.

[avenga]

Also another place they like to leak is through the gasket behind the brake booster and where the throttle and clutch cables come out of the firewall.

[kierbear]

You can tell its the heater hoses when your shoes fill with water haha