Billy, flashing lights attract the eye of the cagers. Why? For your safety of course.
Works pretty good but I find it distracting - which is its purpose. On bikes I can excuse it. On cars it pisses me. The eye contact people are talking about it them probably going WTF and giving a good eyeball.
I had blinking breaklights on my last bike and will put them on the big bastard too.
If I'm worried that drivers arn't paying enough attention I put my full beams on and switch them off when I feel confident that I'm passed the danger 8)