Heh. I have a pack of cigs in my glove compartment right now. It's an old, nasty, stale pack of Virginia Slims. The tiny kind that look like little straws. Horrible crap. But just knowing that they are there and that I could smoke one if I wanted to somehow makes it easier not to smoke.
I was the same way. I had half a pack of camels in my work truck for about a year after I quit.