Brought mine into court on accident once. When I pulled it out of my pocket to go through the metal detector the cops asked what it was, but not suspiciously. Told them and they became very interested in it, asking where I got it and stuff like that.
I brought mine to Jury Duty on Monday. Evod VV/Protank 2 mini.. I put it in the box for the xray and nobody bothered me.
I was puffin on it waiting for selection but I didn't blow clouds.. kinda held it and blew out slowly. Didn't want to attract unnecessary attention.
As far as in the car I do my thing. Never been bothered.