I've sealed the windscreen but water is still getting through. l recently had some work done on the fan motor - might this have resulted in the leak? The garage of course said 'it is nothing to do with us'. Any thoughts?
Thanks

The drain for your air conditionong unit may be plugged. Any service shop can fix it in seconds by simply running a probe in the drian and opening it. You could do it if you know where the drain is.
Had this happen to my twice.

if its just water sit in car have someone spray it with a hose. you sure its not coolant or the heater core

Could be a door seal perished on passenger side.Is your washer jet working ok on the wipers,sometimes the pipe can come loose.If you have a pollen filter on the bulk head then sometimes the seal on these comes loose.

If you have a sunroof, then the drains in the frame are probably blocked.
If not, the drains in the scuttle panel in front of the windscreen are blocked - look for little rubber 'flaps' in the rear bulkhead in the engine bay.

the front air intake the big vent in front of the windsceen when it rains there is a drain on ether side to let water run away may have been dislodged and is letting water in. dontknow your car some bonnet higes have a pocket to sit in they have drains thru the dash as well

l could give you the number for Noah. He has a big boat.

sun roof or aerial socket . or wrong windscreen fitted if replaced .