I had one last week. My first commute in 2.5 years. I'm stopped at a red light, she pulls up on my left, her window is already down, and says "Excuse me, you really ought to put something on the back of your bicycle to make you more visible. You're outfit is very good but..."

My Nova Bull taillight had gone out a few miles previous. I already knew this and told her "Thanks, I have a very bright taillight but it just stopped working this morning and I'll have to troubleshoot it when I get home. You should see it when it works, it's really bright." I think she was genuinely concerned for my safety. It was about 6:15am and still very dark out (and cold).

Just waitin' for my Radbot and I'll be back out there.