I thought I'd forded the two 800mm deep rivers without getting any water in the GU's cab, but a couple of days later discovered some had seeped in on the driver side. Finding where it got in was a bit of a mystery, but I think that has now been solved.
In the DX ute , possibly other GU's too, there is a clip on piece of plastic trim on the floor which straddles the door sill. Inside the cab it has 4 'pins' which insert into 'rectangular' plastic receivers which are a push fit into the floor pan. One of these has had a hole smashed in it underneath the floor. For now I have wrapped it in tape & smeared silicone over that.
Can anyone tell me what these 'receivers' are called or give me a part number for them?