Ah, I see what the problem is: all this time you thought I was the one who brought up the topic of the guy hearing her? I brought up peeing; therefore peeing had something to do with her reasoning;
The problem with the anecdote, the best I remember it, is that it was described but included nothing about her motivation or the context.
Someone asserted that she's probably a prude. I pointed out that she might be the victim of a nasty trauma in the past. There are other possibilities though. Maybe it was a political statement about office politics. "I don't like the new boss and they said that male women are now entitled to use the women's restroom. I'll just go out to my car and hang curtains so everyone knows I am pissed!*"
Honestly, the idea of a woman peeing in her car is kinda over the top. How would one even do that? It's easy if you're a guy, I've peed in my car while driving it highway speed. But I have male fixtures, it was not even difficult.
Tom
*Pun intended