You shouldnt be on the white line on a right hander Dave - maximum vis is given by being on the left side . Particularly key in a RHD car.
I'm wary of the sudden noise argument. Used by a lot of bikers to justify loud exhausts but a loud unexpected noise certainly causes me to flinch. Particularly relevant in a traffic jam when bikes are filtering between lanes, and drivers are dozing. Yes I know we shouldnt doze but certainly I find it difficult to maintain full concentration in nose to tail slow moving traffic. Sop its easy to imagine someone startled by a noise involuntarily jerking the steering wheel.
