At the supermarket car parks in north London, it is the same group who come every year, tour the supermarkets in the same order moving every 2 weeks until they eventually leave. So it could possibly be the one family.
OP, we have a large amount of travellers descend on us every year. I have seen;
That awful situation with the kids and baby being badly hurt because they were playing in a car park
3 semi naked men washing in a car park with a shared bottle of water
Grown adults pooing in Ikea car park (I don’t even understand that one, Ikea has toilets)
Baby’s being washed in Nando’s toilets
I know it’s not you personally as you’ve said you don’t pull up in car parks but I don’t mean to sound rude or nasty to people that do but honestly how can anyone enjoy a life like that?