wanted/recomendation for a A8 cover

[daviesbike]

hi all i dont have a garage for my pride and joy and where i live its right on the sea front and the salt air is not doing my fresh paint job any good im wandering what size of cover i would need to cover it right down to the wheels bay but there are so many sizes like large xL xxL xxxL ect ... any recomendations ??

i only use the car on weekends and when i come to use it its filthy despite me cleaning it all week ?

many thanks