Update II.

Finally managed to plug the leak on the passenger side with plenty of silicon around the bracket where the water was running through. Have used the car for the last couple of days in some very heavy rain and havent seen a drop. So I've decided it's safe enough now to refit the headliner. Lets hope the fix is good enough.

As for the carpet. As advised, unbolted the seat (surprisingly easy - thought it would be a much more complicated process) and raised as much of the carpet as I could. The foam underneath was saturated and there was sitting water in the floorpan of the car.

I squeezed out and mopped up as much of the water as I could then put newspaper underneath and replaced the carpet to soak up additional. After that raised the carpet again so that air would circulate, turned the heater on full blast and left the car run for a while. That has helped dry the foam out even further.

But it will need a few days in dry high heat (not something we get very often during a British Summer - it's raining and about 18 degrees celsius today) to really dry out. However it's lot better than it was and doesnt feel sodden to the touch.

At least I can now go on holiday later this week with some hope that we're not going have water pouring down the A-pillars into the footwell as I did a few weeks back. Not much fun 500+ miles from home with the family in tow....

Thanks to all the advice folks. As someone said it's pretty poor form on a car that was circa £50K new to have such a design flaw.

Also (didnt mention first time round since this problem was occupying me far more) replaced the FSR too. The aircon had become erratic and I was worried about a big bill for this until I read on this forum about this common problem. £63(GBP) from the local Stealers and 15 mins to fit myself.

Hopefully that's the end of my problems for the moment. Aside from these issues the car's great. Big 4x4, especially X5's and especially V8 petrols are really out of favour in the UK and as a second hand buy they're great value. Of course it may be more interesting when it's time to sell on but I plan to keep this for a while.

Looking forward to heading off on holiday next weekend. Driving the family to the South of France for a couple of weeks and persuaded SWMBO that we should go through Italy - via the Stelvio Pass and a few of the other interesting driving routes. Cant wait.