I have noticed people treat me differently in traffic in different parts of town depending on how I am dressed, and depending on what bike I am on.
I live in the athletic part of town. Oddly enough we have one. I live less than 6 miles from 3 bike shops and a co-op. Near several of the highest peaks in town, and the main course for most of the marathons and longer races and what not, means you have to remain aware and park accordingly or you may end up stuck on a sunday morning by runners. so there are constantly runners and cyclist passing in front of my apartment building training.
Over here you get ignored pretty much if you are on a bike.
Downtown if I am in kit on a bike people are pretty nice, doesnt matter what I am riding I get the right of way at lights and in some cases people give me the lane. But if I am in jeans and a t-shirt, it is a bit different, even on my tri-bike people can be mean. At least the cops are nice. (usually)
Out in the suburbs it doesnt matter what I am wearing. They pay attention to what kind of bike I am on, if I am on a nice bike they are a bit nicer, people go around me, or give me the of right way. But if I am on my fixed gear people have buzzed me or I get the finger, but I rarely get horns blown thankfully. ( there have be exceptions. I have been out in full kit on a road bike and been stopped by a cop to ask me if the bicycle was stolen)