Someone asked about a top box and bars. If you want something that is good value and a good size try this combo-
http://www.ebay.co.uk/itm/Roof-Bars-...&_qi=RTM756412
I received mine last week and all is good apart from a mis-shaped U bolt which I'm chasing up. Not much noise when cruising at 80mph.
All ok for a couple of times a year extra capacity.