Yesterday a deluge dropped 2.5 inches of rain in Baltimore. During the deluge I had to ford at least 24 inches of water in my Mini Cooper S. I drove through several streams that had balsted over the bridge spanning them, in the track of some trucks. I don't recommend this in a car with a low intake (like an older Ford Escort, but that is another story).
the intake is in a great place for deep water fording, even when the water came up over the hood once, the Mini kept going.
the Mini is not water tight, some leaks were noted around the tranny hump and a few squirts came in through the door sill, but it was only a few little squirts.
Keep the a/c on no matter what, the deforsters just could not cope.