When going around any 2 lane roundabout, or one way system, try not to be absolutely level with the car in the adjoining lane. If you are slightly ahead or behind, half a car length say, a quick tap of the brake or accelerator (as appropriate) will get you ahead of, or behind, that car, should it try to change lanes with no indication. This has saved my bacon from people that dont have a fucking clue how to drive roundabouts three times.

Does that make any sense?