roof bars on a mk 4 renault espace

Hi All I have a Renault Espace 2004 1.9 dci and want to fit the genuine roof spoiler/bars, I don't see many on eBay so wondered is it possible to fit the Mk 3 type spoiler/bars onto the Mk 4? if I was to do they fit straight onto my runners or do I need extra parts that I hope would come with the 2nd hand roof bars. Many thanks. Doug. :)