To cut a very long story short some years ago I bought an approved used BMW car from my local dealer that had apparently gone through an extensive pre sales check to comply with the BMW Approved warranty scheme. I then had to take it back a few days later for a nose off the rear nearside wheel and they came back to me with an extensive list of faults that needed rectifying but it would all be covered under the warranty.
Feeling aggrieved that this supposedly thoroughly checked car had developed so many faults in such a short time I smelt a rat, if they carried out the work prior to sale it ate into their profits. If they said they'd checked it and then found the faults BMW's warranty scheme paid for it and they maintained any profit margin they had in the car.
What they didn't account for was a cynical copper, as I was then, contacting BMW UK who sent down an engineer on the agreed date that the car went in walked through the door just behind me, took the keys from the Service Reception and demanded a ramp be made available for him to inspect the car. The car was returned a week later, having been loaned a brand new demo car for the week, with all faults rectified and a large bunch of flowers for my now ex wife. The engineer stated that the defects could not have occurred in the short time I'd had the vehicle and the dealer was to repair them at their cost or BMW UK would take punitive action against them as a dealer.
From that day on the service I received was nothing short of exemplary!
Sorry not quite as short as hoped, I guess now their warranties are provided by a third party and it's not them being ripped off they don't care?