Water leak, any ideas

Hi folks,

I have water in the passenger side rear footwell. Before I go mad stripping the car down does anyone have any experience of similar troubles.

Thanks

Steve

I had water and i think it came from the drian away. Mine had rusted through. To the left of expansion tank you will see an over flow drain leading from the space where the wiper motor sits. Mine was blocked but directly below it there were a couple of smal holes. Filled them with roofing bitimin until the car is resprayed. I can get a pic if you can't find what i have poorly described.

only experience of water in rear foot well came from sunroof drains and  have also had problem with boot seal, but if you don't know history of the car it maybe worth checking see if rear window is orginal bmw incase its been replaced badly and not sealed al way round