That would be more likely down to Vauxhall rather than A/Cs. Should have been picked up during an inspection when the car came off the transporter though.
I personally would prefer to spend extra for a car through a franchise dealer that's had to meet brand standards for a used car than a non franchise that can run to their own standard. Having approved parts fitted by a certified technician is an option I'd far rather take.
I know. Still found it funny though and it's always been at the back of my mind when driving past Arnold Clarks.