I can speak to zipper merges since i go through a couple on my commutes. I think that part of it is that people see a nice car and assume the driver cares enough about the car to back out of any forced merge or lane change. In terms of following distance, I feel that I haven't had any more tailgating than what I would experience in a "normal" car. Following distance may be a bit closer as mentioned. One of the merges on my commute happens about half a mile after a stoplight so it's always fun when anyone tries to race you to the merge in their Accord.