Vauxhall Omega (aka Leaky Lily) rapidly filling with water

Try pouring water down the sunroof drain channels and seeing if it's draining out properly through the bottom of the wings.

Cheers, Jiffy

There is also a couple of drain holes under the bonnet in the wings which drain off the water flowing off the windscreen. They should have little plastic sieves on them, if they get blocked with leaves the water can build up and leak down the wiring loom into the car.

Will

There is a drain hole underneath the plastic cover around the windscreen wipers and if that gets blocked water can fill up and overflow into the air intake and from there run down into the passenger footwell. I think you can see it if you open the access flap to the pollen filter (on the nearside just below the windscreen). The drain hole is in the center of the car at the bottom of that void.

Guys,

Thanks a lot for your very good (and clear) advice. If it's not weeing down on Saturday, I'll be up to my elbows in car muck :)

Cheers

Rich