I was on my way home one Friday evening on a busy city blvd, lo and behold there was a sobriety checkpoint ahead and I was already in line. No need to panic, I wasn't drinking or carrying drugs or running from the law, nothing to hide.
I was well into in girl mode and I continued in that mode. I checked my lipstick and hair and waited for my turn.
My window was rolled down as the male officer leaned towards me and asked how I was, making eye contact with him I replied with a smile and carefully said, "Just fine thank you". He smiled back, glanced at my rack, and waved me through. My heart didn't even speed up, my breathing remained regular, I didn't break into a sweat, I was very calm and I believe that he saw that.
It saddens me to read about all these bad times that many sisters had to endure. Yes you can be honest and calm and all that, but it only takes one 'bad or curious cop' to make a harmless situation into a bad one.
I go on police ride-alongs periodically and I do talk about such issues with them. Basically, if you aren't giving the police a reason to draw their attention towards you, you should be okay out there. They have a lot more on their plate to deal with than looking for CD's to harass.
Of course a cop working in a rural area or small town is probably bored and is looking for anything out there that seems 'unusual' to them and worth investigating.
My rules include always being where other people are. I do not park in empty lots at night or walk downtown after the stores have closed. Those acts will attract their attention as that is their job.