I've had the benefit of general advice before about leaks - most useful, but now I can talk more definitely. I finally traced one water leak yesterday, but need advice on how to seal it for good.

After pouring water into the heater box grill below the windscreen, I watched with the hood open and most of it came out, as it should, through the pipe and onto the ground, but some seeped out from the side of the heater box. Looking inside the car, some of this water came in at the edge of the box and ran down to the floorpans.

Do I need to dismantle the box from the engine side and what do I need to look for as to why all the water is not running down the pipe as it should? Is there a new seal I can buy and then just screw it back real good, or maybe a beading product (like plumbers use around baths) could be used?? Just grasping at ideas.

The other leak is more difficult. If you look under the dashboard above the parcel shelf, there is a small black box with two screws. What is this box? Anyway, water is dripping down one of these screws and landing on the parcel shelf. Is this likely to be from the heater box as well?

From a rainy London, to all you good folk, a plea goes out. Help me get the rain out of the car onto the street, where is belongs!

Thanks guys!