How do I get the best boot space in the Tarraco with seats folded down?

I've got a Tarraco and I'm trying to get the most boot space possible with the seats folded down. Problem is, it's not really cooperating - even though they're flat, there's still quite a gap between them that's eating into my available space. Does anyone know of any solutions or mods that can help me eliminate this and make better use of my car's capacity?