This is a classic example of good scientific research that counter-intuitively confounds our notions.

http://sciam.com/article.cfm?chanID=sa029&articleID=778EF0AB-E7F2-99DF-3594A60E4D9A76B2

Blacknad.

Strange as it sounds, I think the "Research" is accurate. I was an avid Cyclist years ago, before the "Green Movement". I felt, after starting to wear a helmet, that cars weren't giving me as much room as when I was riding bare-headed.
Another thing I noticed - when I converted my car to Natural Gas, I had a Bumper Sticker on the rear, "Powered By Natural Gas". NO tailgaters, Never, Never, with that on the car.

Wow,
Very practicle knowledge, and as you say, a good demonstration of how issues can be very complex and multi-leveled.

"If you really want the greatest passing distance, you should wobble down the road," looking as inept as possible, he adds. --from the article.

Those are the ones to whom I've given the widest berth!

~SA

He also says if you do have a crash it is 98% to your advantage to have been wearing a helmet. Seems OK odds to me.