Something similar happened to me when I went to buy a puppy in 2008.
There was an advert somewhere on one of those animal / pets sites, like an eBay for pets.
Anyway, the woman on the phone gives out her postcode and says I'll direct you when you get here, because it's hard to find. I arrive at the postcode, it's a row of council houses in Grays, Essex. Sorry in advance to anyone that lives in Grays, but it's 99% shithole. As I pull up, a guy in a Vauxhall Cavilier gets out and asks me to follow him. We're driving and i see a rough looking tower block on a council estate in the near distance that we're heading towards. We drive past the estate and the road starts to get very rural and narrow, the sort of road that people only drive down to dump rubbish.
He pulls in to a gypsy camp site.
It's difficult for me to do a U turn and drive off. I'm quite ballsy, having grown up in a rough part of East London, so I put my big boy pants on. My out of place car attracts attention of the kids on the site and they gather around. I style it out.
The guy takes me to his caravan, and in to the garden / pen attached to it, where there is a litter of puppies. His wife comes out, introduces herself, asks if I would like a cup of tea. We discuss the dogs, I see the mother and father of the puppy, I buy one and hand over the cash.
We had a laugh about the shenanigans of following their car, but she said they don't have their own postcode, and nobody would come if they gave out their location 'the gypsy site'

They were the nicest, friendly and lovely people, and the dog lived for 13 years.