Hi, my Focus mk2 has been letting in water. It's only the rear, passenger side footwell that's affected. I've had an indie look at it and his initial inspection (water testing, removing door trim/carpet, etc) couldn't find the cause. He asked if he'd like him to continue looking at a cost and I decided against it. The carpets have been dried and the rear passenger window no longer steams up.

My question is this. I was washing my car today and noticed that the rear wheel arch liner on the passenger side was missing missing a screw and therefore could be pushed in. Could this be the cause of the water leak?

Afraid not, the wheelarch liners aren't supposed to be 100% watertight so even with a screw missing that shouldn't cause a water leak.

Could be a problem with where various flanges of the body have been sealed, if you're able to remove the interior trim from around that area then spray water over the top of the car and see if you can spot where any water is coming in you can work from there. Could even be a leak up at the roof seams which works it's way down the inside of the car and ends up in the footwell.

I'd have a good look at the door seals too. Again, if you've stripped out the trim and dried everywhere first you can then spray water around the door and see if any comes through into the cabin.

Thanks for the respone. I'll just have to keep looking.