The Costco's that I've visited seem to do a pretty good job of keeping their lots clean. It's Wal Mart that pisses me off to no end. The one in Decatur, TX will have fully 90% of their ENTIRE inventory of shopping carts piled up everywhere in the lot. There IS no safe place to park in this lot, and the cart corrals are useless when they are overflowing. I also park way out of the way in these lots, just to stay out of the way of the beached whales idling away in the isles of the lot waiting for that front spot to open up.
If it wasn't for the fact that they've killed pretty much every single business out here, I'd never set foot in the place.