We do that often, when we go into town, my husband and I. Granted we don't live there but we do go in usually a couple times a week, so you'd think... but no. You (or we anyway) tend to pay attention to the things relevant to yourself.
I inherited the messiness from my parents
A coworker had a college son who chewed. He was a spitter and had half filled pop cans of spit all over his room. His mother cured him with only one try. She emptied all of his spit cans on his clothing.
I put the cup in the console after that. 
I forgot to mention that the clothes that she poured the spit on were the ones that he had just finished folding from doing the laundry.
I used a spit bottle and always kept the cap on it between spits.I used to drive with a spit cup between my legs (crotch area). One day during an emergency braking I spilled it all over myself. That stuff burns.
Chew is not the number one cause of mouth and throat cancer.
