If it's a roller blind type then it's not for split seats. Split seats have this type and it 'hangs' off elastics that plug into the sides near the top of the seats:
http://cgi.ebay.co.uk/PORSCHE-968-944-L ... 3a56dbc63eStupid money for a worn out bit of badly faded rag. Mine looked just like the one on Ebay, but was torn so I stripped out the workings and my wife made me a new cover out of poly-cotton canvas edged with nylon Petersham. Total cost £6 and a few hours work. It's amazing, and when I work out how I'll post pictures.