Citroen call them roof bars. There are 2 different ones depending on the car date of manufacture (from the rpo number). Plus you need the front and end bits and the threaded fasteners and nuts to bolt them to the roof and new strips (mouldings) with cut outs that go under the roof bars to replace the ones you have. I had a quick look on ebay with the bar part numbers and could not find any so maybe you would need a scrap car or to go to a Citroen dealer.
Up to RPO 12585 you need
- bars 8361L4 and 8361L5
- mouldings 8320J4 and 8319P0
- end parts 8361L6 and 8361L7
- threaded fasteners 8301EG - not sure but you might need 8 of these but there could be 4 in a pack
- nuts 6935C7 - not sure but you might need 8 of these
From RPO 12586 you need
- bars 96767800VV and 96767801VV
- mouldings as before
- end parts 1607083580 and 1607085780
- fasteners and nuts as before
These part numbers should be checked using your VIN. If you do make the change then the modification will need to be mentioned to your insurance company but it ought not to cost anything unless there is an admin fee.
You can see the parts on the parts diagrams which you can see as a free service if you register on the service.citroen site as an other professional non emergency services and as a member of the Citroen Owners Club. Once on the site use your VIN top left to find your car. The bars can be found under Bodywork, Roof, Roof Panel. http://service.citro...angerParametres You might need to select your language first.
This old ad shows the bits https://www.gumtree....ails/1183051405 I have read that to fit the new fasteners some torx bolts need to be removed which can be difficult since they have sealant on them. The new fasteners will also need sealant. If you have the panoramic roof the part numbers may also be different.