I never really understood the whole "hear that huge SUV being me" thing. I mean do you actually change the way you ride based on hearing a car behind you? I can't even imagine stopping or moving off the road every time I heard a car - tons of cars drive by me on my commute and I just keep on riding. I do everything possible to be visible and safe (lights, bright clothes, etc), but there comes a point where I just accept the risk of commuting.