I used to keep weed in my car becuse i had a wife that didnt like the smell in the house. It certainly dried out a little more than i would have liked, but i didnt notice any other adverse effects. The weed still smoked beautifully!
I now use a large clear plastic container for storing larger quantities, that has no smell of plastic present, and it has a lid that snaps down on all four sides. Its great for keeping the smell in. And for small amounts i use a 35mm camera film container. Again great for keeping the smell at bay.