Inside the Little Plastic Castle

Not exactly. Since passage of ADA, most large stores have wheelchairs available inside. The manuals are heavy depot clunkers, designed to be pushed, not self-driven. The power devices are very basic, mostly three-wheeled, with a large shallow basket in front of the tiller.

This brand used to dominate:
http://www.amigoshopper.com/products/motorized-carts

The ones delight appreciates so well look like


The Target carts offer a big basket plus a shelf underneath. That underneath shelf sports rollers on the corners, preventing naive users from getting hung up on displays. As with most shopping carts, the sear is very uncomfortable, with a low back, and they have undefeatable back-up beepers.

But these devices are only available for use within the owning store. Personally (some insurances will also cover) you can rent a powerchair/scooter from a durable equipment store. The drawback there is these rentals are hard-used, indifferently maintained, and generally bottom-of-the-line models.