I know this post is wayy far from the first post. I apologize for that. I have gone to the link and perhaps the info. has been altered or updated.
As for roof : xfire roadster has choice of roof up or roof down, unlike xfire coupe that has standard roof.
As for seat : different series of xfire, roadster or coupe, has different material for their seat, that comes with different pricing.
That much I know
As for me, I am still having the factory wheels of front, 18 x 7.5" and rear, 19 x 9.0" which lead me to my question, next.