Ran into a ninja last week. While in line ordering some subway around work I see this HB9 (very rare where I work) walking by looking at me and smiling. I smile back for a couple seconds, pay for my food, turn around ready to open and shes gone. I look around for a bit and see her as she was driving away.

This morning I saw her car a couple buildings away from where I work (its not a common car). It's a small area where I work so I'm sure I'll eventually see her around again. Question is should I wait till I casually see her around or leave a note on her car?