i smoke in public all the time,
in fact i do it all the time, like if i gotta go the shop ill roll a joint for the journey
my mate used to deliver chineese take away at nite we used to just by an 8th deliver peoples meal and roll heaps of joins it was a good laugh, got stopped by the police a few time, never once did they suspect we were smoking weed, and if the wanted to search us or they car they would have found it, we just made sure the window was down when we smoked it and there wasnt any skins or anything relating lying about in the car