They werent just for the Roadsters. They were an optional extra on top of the GT pack. On my 2007, if you went for the GT pack you got the black leather seats and you could pay an extra £600 (I think it was) to go for either the Frost Grey/Blue or the Alezan Orange. Both are an acquired taste, so a lot of people didnt bother.
Where the Roadster seats are different is that they are vented, so the seat back has like a fishnet style material rather than being solid like on the coupes.
So those seats in that car are Roadster specific then, just like I said?