these very rarely come up for sale sadly :-( i take it your after the blue one with the bmw logo on the bonnet?? its a fleece material inside and super stretchy outside, these are great and very high quality....
Also assuming you want the genuine one? I bought one off ebay and it fits really well. It's not waterproof but did a good job of keeping leaves and sap off the car when I had to leave it in a friend's very leafy tree-lined drive. Have had a look but the seller doesn't have any more advertised at the moment.