My children have been sleeping in shopping carts since they were toddlers. It actually makes shopping very nice. You know, all the quiet is good for shopping concentration. (After reading this over I realize it looks like I have shopping carts in my house and that I use those as their beds. This is far from the truth. My children just have a knack for falling asleep in the car on the way to the store which means I must a.) go home or 2.) put them in the cart to nap while I shop...okay, you may continue reading.)
I have had to adapt all kinds of things for padding and pillows for better comfort in the shopping cart: slings, purses, coats, towels, and blankets.
Then there are the things I have purchased when a child has fallen asleep in the cart mid-shopping trip for a more comfortable (ie: longer) nap: toilet paper packs, paper towels packs, pillow (I needed one anyway)...
By the way, on my job description is "very capable of adapting and thriving in any situation"!