Today’s invention is a town car especially designed to enable shopping.
This would have a notch-shaped dock built in between the back seats to accommodate a shopping trolley of standard size (but perhaps better engineered to be lighter).
The trolley, which would be supplied with the vehicle, could be detached from the car, via the open tailgate, and used to collect one’s supermarket haul.
On returning, the tailgate would be unlocked and the cart rolled into the notch which would contain a shallow ramp. A motor would automatically drag the shopping up the ramp (so that the trolley wheels would be well clear of the road) and lock it in place within the vehicle.
At home, the trolley could be detached again and conveniently wheeled into a purpose-built cupboard in the kitchen.