The claustrophobic confines of a west London attic hideaway. Walls, covered in heavyweight purple curtains seem to bring the dimly lit room's parameters collapsing in as a huge computer screen’s wallpaper radiates the green glow of long hot summer. Its pastoral image of feudal tranquillity is the room’s only window on the world. Look closer and there's a twist in this Constable painting. In the middle of the painter's rustic overtures sits a stolen burnt out car. It's an urban blight on England's countryside, a twisted interruption on this green and pleasant land. More than just a screen saver though, the image, one of Banksy's infamous reworkings of old masters, is the perfect visual accompaniment to the aural assault that is pounding from the room's speakers. Sweat soaked b-lines thunder with