Roof Box - getting desperate

[AJM]

Just bought a Mont Blanc roof box, which stated on their website that it fits the Berlingo Multispace 2004. Well it doesn't! The factory fitted roof bars/rails on the car are too wide for the hole spacings in the box. Does anybody know which roof box will fit my car? I have 9 days to sort this out until going away to France. My Citroen dealership quoted silly money for a box, but even they couldn't say if it would fit. The problem is the roof bars I think, I could buy a new set of roof bars but they are on the roof anyway so why buy something I already have? All I need is a list of roof box make/models that will fit to the existing bars - any clues people?

Thanks for any advice, I'm sure other people have had this problem.