In college me and my roommate had a smoking room.  It was also the party  room for the dorm, (obviously) and there was always someone smoking in it etc. When we took our posters down we had darkened the paint down 3 or 4 shades.  It was pretty, well at the  time we were impressed.
I will say, vapes may explode but the way my car used to be (oh my and especially the VW?) that was DANGEROUS, man there had to have been over 100 holes in there, I stopped counting.  I had to extinguish cigarettes that flew back into my car and lodged  between the seat and my back by leaning BACK if I was on the wrong type of road.  That was pretty dangerous (and painful) kinda thinking harm reduction in many areas, LOL.
Anna