It seems to be not uncommon for people to follow shoppers out of the shops and back to their cars to take parking spots, but the car park as a whole is never designed to allow for this. What if the entrance to the car park was close to the shop doors and there were pedestrian walkways beside all the major car paths to allow for easy following?
Mokalus of Borg
PS - Parking is easiest when everyone arrives at once to an open-plan parking area.
PPS - Then you can just file them into rows as they arrive.