I remember riding in Flanders and a tractor pulled over to let me pass... as I rode by I said thank-you, probably with a look of disbelief on my face, and he said "Here, you are King.".....

Back to a group riding two abreast... it's far safer for the riders that way as it forces cars to pass wide... the group should be viewed as a "single vehicle". Well drilled groups will string out to let cars by but drivers just have to have a bit of patience... is anything really that urgent?