[hotz]

Aftermarket exhaust and slight left/right swerving movements beats hi-viz. The swerving is meant to catch the eye's attention in the side mirrors.

Many people also drive with earphones on so whatever external noises they hear is debatable. I'm betting most bikers will agree that hi-viz alone doesn't guarantee that you're visible.

[Enginerrrd]

Not sure I agree with the exhaust, but the weaving seems to help a LOT.