I have been to "Big Motoring World Group selling Second hand used BMWs, in Kent, BMW 1 Series, 3 Series, 5 Series, 6 Series, 7 Series, X3 M3 Z3 Z4"
Can confirm the non-existant car stories. I stopped in there once when I was passing by after seeing something on the internet that morning.
They tried to make me look at a "similar" car, which was some dodgy spec and not anywhere near the good value the advertised, non-existant car was.
To me, the whole set up felt completely wrong and I would not have bought so much as a can of coke from them.