Cadillac vs. Mercedes

Yesterday, I had two different luxury cars behind me for most of the way to work: a Cadillac and a Mercedes. The Cadillac sat on my tail as close as it could get, but the Mercedes stayed a safe distance behind. I saw it coming in my rear view mirror. It was going a good 5-10 m.p.h. faster than I was, and I was fearing another tailgater. Then, as it started to get closer, it slowed down and stayed a comfortable distance back. Another totally unscientific data point in favor of Mercedes drivers.