For quite some time I have kept a clothes basket in my trunk. It really makes unloading groceries from my car so much easier, especially with all those plastic bags!
There are quite a few "trunk organizers" out there. The only problem is that are they expensive and they don't really help with getting the groceries (or other items) from the car to the house!
Clothes baskets will also help keep things like back packs, sports supplies etc. all stay in one spot. It also makes a great place to put all of the items we need handy such as paper towels, a couple of trash bags (those empty plastic grocery bags), kleenx, wet wipes, umbrellas etc.
Overall, it's just a practical and SIMPLE idea to make your day just a little easier! Just remember to put the laundry basket back in the car once you've emptied it! :)