I also use a trailer for grocery shopping, I think it's called the revolution. It really is not much more than a large ice chest with big wheels, but it does a fabulous job hauling the weekly grocery stock. It also has a lid which keeps things dry. For extra space, I have a foldable wire basket attached to one side of the rear rack (I do not have a basket on the other side because that is where I clip my bike briefcase on my commute each day), and of course there is the rack itself. Honestly, it carries all that is necessary for two people, two freeloading cats and a demanding basset hound. The grocery is at most only three miles away.