Our plastic bag storage cupboard (bags reused for garbage) is so jam packed the door almost doesn't close. Given there is only one person who brings home shopping in plastic I was looking for a powerful message to go with my suggestion of keeping reusable bags in the car and actually using them. Searching for graphic images of the gyres garbage dump I came across 22 compelling facts about our obsession with plastic. Read them here. I am sure you will find some that suit for those you want to change their plastic behaviour.