I do believe in adjusting somewhat though "when in Rome" etc. to blend or be understood. But also the other people have to meet people not like themselves part way. That's how it should work,anyway.
I see this point of view, but I also see the other side of it. If the PTA member was going to work in expensive designer clothes and wearing different expensive jewelry every day, I can see changing. Maybe not in the car, though. Maybe at work or at home.
I once went to a fast-food restaurant with someone wearing a very expensive fur coat and a lot of really nice jewelry. We had come from work, and this was how people dressed there. No one said anything, but we both felt out of place. I can see that people who are struggling to make ends meet would react negatively to seeing someone dressed like that at every PTA meeting. Not to mention that by advertising your wealth, you set yourself up to be asked for donations again and again.
I also understand that you can't predict how other every other person will react to your clothes or speech habits. But that doesn't mean you should use that fact as a reason to do anything you like and ignore how most other people might reasonably react.
