Is there a custom rubber mat? They work well to catch all the drips.

I took my car to a panelbeat.He gave it the full rust treatment for a couple of hundred : )

Does anyone do the spray in ute liners there? That would be the ideal.
Next would be any of the auto underbody bitumen type products, applied thick.

Easy and cheap, give it a spray with de-odorised fishoilene around the seams (only), then gaffa tape in thick plastic sheeting across floor and about 10cm up the walls, then a big bit of carpet cut to size.

The rubber mats are great at trapping sand and moisture underneath

I repainted my floor and added a waterproof plywood pannel, which is sealed with sylicone at the edges.
I was also able to fix the furniture in without making many holes into the sheet metal.

Floor tilers use a rubberised, paint on membrane in bathrooms to seal everything before they tile.
This stuff is great on the floor and 15cm up the walls of my van.

Hey Sean,
Great choice on the H1...it will make it so much easier to fit all our gear in when we come to visit!
Not sure if this helps but I bought a hiace van last year which had a rubber floor already installed. After some research I did the following:

1) Strip the existing floor (it was glued) and removed any glue residue etc
2) Silicon any holes in the sub floor (the hiace has all sorts of bolt holes and mount points) with marine silicon
3) Apply a non odourous fish oil to the floor. Let it dry and repeat.
4) Apply a layer of plastic and gaffer tape the edges about 15 cm up the side walls
5) Install a sound proof mat in direct contact to the plastic
6) Install an absorbant layer (ie like a chamois) on top of the soundproof to wick away any moisture
7) Install a rubber floor over the absorbant layer.

I live close to the beach and my van is such a permanent fixture at Inverloch beach carpark that I think the council wants to charge me rates ! The van is outside in the elements and so far, there has been no moisture and sand underneath the rubber mat.

cheers,
Mick