The medium size full car cover from Halfords works well, I've also got one made to measure for my ex +8 made from Noah barrier fabric which is soft on the inside and still fits the Aero (cost about £200) which I now use in the garage.
My only warning with the covers is that high winds make them flap and this risks bruising the paintwork so if possible park in a sheltered spot.
Love your choice of colour by the way, from a fellow BSB
