I was reviewing the LeisureLines.net website today and happen to take a look at the link they had for Ducato/ProMaster Vans. I'm getting ready to start my build in April and had pretty much convinced myself that we would use Jerry can's to store our fresh water and gray water but am reconsidering this after seeing this custom built tank. It's notched to allow for the ribs in the floor and is designed to fit between the main supports and the emergency brake assembly. They have from 14 to 20 gal tanks. I'll check to see if they'll ship these to the US. My build will have a garage storage area and don't want to use it for a water tanks. I've seen the tank that's shaped to go over and around the tire cove but will keep my options open.