i love pumping in my car. i know that may sound odd but i feel like its my own space.
i agree with weighing your options. I really want to be able to pump when i want and for how long i need. i feel like if i were really pushy and made a scene about it then i wouldn't have the freedom i have right now. when i travel i do push the issue a bit, it depends on the situation. if you are not comfortable then find another option.
women have been pumping in the bathroom at my work for years. i even did with my first. for whatever reason it really bothered me to have to do it this time and i realized there was a room that was used very infrequently. so i spoke with people who use that room (its a recording studio) and asked if i could pump. i said if they needed it i would find something else for that session. they were fine with it and our use of the room has not conflicted yet.