After a couple of days of heavy rain, I was driving to work this morning when the windscreen started to fog up.

When I turned on the blower to maximum to clear the screen, a considerable quantity of water sprayed out of the vents and all over the centre console.

Does this suggest that I have a leak/crack in the ventilation system somewhere? I don't like the idea of water sitting in the pipes ...

Hmmmmmm, do you park the car under a tree?
Sounds like the cowl drains are plugged and full of water to me.

Depending on which model/year car you have, there are a couple of drain hoses that exit either through the firewall or the trans tunnel (under the car).
These drain the water that gets into the cowl area, and they can get plugged with leaves-dirt-debris etc.

Usually a straigtened out coathanger or similar type of "tool" can be used to clear them.

__________________
Alain
independant MBZ tech since 1981
http://www.motorsportlegendsks.com/