Where can I buy a little sensory overload?

I had an experience yesterday that gave me a better understanding of what it might feel like to be inside my son's head. I was already on edge because of my ingrained Check-In Anxiety (see yesterday's post), and although our check-in had gone fine, I was mistrustful of any apparent well-being -- maybe the way my son feels about any transitions, however small. We went to gather some groceries at a Wal-Mart Supercenter, and from the moment I set foot in the place I had an almost visceral need to get the heck out of there. It was crowded and noisy. The aisles were too narrow. There were incredible amounts of stuff laid out in patterns that were indecipherable to me. They say that kids like my son experience the world as frightening and fragmented and aggressively disorderly, and they have to build elaborate structures around and inside themselves to cope. For 40 minutes or so, I knew how they felt. Perhaps Wal-Mart should provide sensory challenge courses for parents of kids with special needs. They seem willing to sell just about anything else; how about a little understanding on aisle 4?