I think for most cigarette smokers, whether former or current, smoking in the car is a habitual ritual.
That goes double for the first smoke of the day when you leave the house.
Since I quit the cigs I've been able to postpone the immediate light up until I get to my favorite coffee shop. It's there that I light my first bowl and smoke it with my coffee (or espresso, or espresso derived drink).
Alliteration!