My DD has 4. Has a 7 seater with sliding doors.
Always parks at first available space even if it is miles away from entrance.
Takes the pram out first. Straps in baby. Then the toddler,straps her into the toddler seat.
Then the 4 and 6 year old get out of the van and to this day still put their hands on the car until doors are locked etc.
They were taught this at an early age.
Then they stay glued to the pram while they traverse the car park.
Actually I admire all mums when I see them out shopping with 3 and 4 children.
I only had 2 and they were 3 years apart. The 3 year old was at pre-school when the youngest was born and I rarely shopped with them both together.
Also there was much less traffic and people around when mine were small.
A friend of mine quite often comments that mums today seem to be harrassed and not quite in control most of the time.
I then remind her that she had two and left them with her mother when she went shopping.