After faffing around trying to find decent fixings to hold my ceiling panels up, I found these:
http://www.ebay.co.uk/itm/50-x-Trim-Pan ... SwEppUMs3E
They are f'ing brilliant! Not cheap but WAY better than anything else I have tried or looked at. Once fitted you will have to hang on them to pull them out. You will need to open out the row of 6mm holes in the roof spar to 8mm - 9mm though first.