Mat Watson goes all Banksy to find out how aerodynamic the new Mercedes B-Class really is by covering it in paint. All in the name of science, obviously.<br /><br />Read our first UK drive here: http://www.autoexpress.co.uk/carreviews/firstdrives/278734/mercedes_bclass.html<br /><br />Subscribe to Auto Express magazine and get 6 issues for £1 plus a free gift: http://subscribe.autoexpress.co.uk/yt
