Please do, and if you could have him put his detailed response/explanation in writing as to why not to fit any OCC on a Stinger, you could relay it onto this forum for all to digest and make a decision on.
However, having worked for dealerships, I've found that a dealer / manufacturer will NEVER condone the fitment of any item that is not blessed within their four walls. When asked about tyre replacements, the standard answer will usually be "fit the same tyre that the car came out with from the factory" "It's the best tyre for this car". And yet, those of us who know tyres will tell you that the Michelin Pliot Sport Cup is a better tyre than the Sport 4 ( for example ).
Even "if" you were to find out that a part that's fitted to a
Genesis G70 3.3TT is exactly the same fit and form as that which is fitted to a Stinger GT
3.3TT but, provides more power and better fuel efficiency ( etc etc ), KIA would not condone it being interchangeable ( it would probably end up being an upgrade in a future model ).
As for people being sent O/S for "master training" on cars, they 'might' have been sent because they truly deserve it but they often are sent because of "other" reasons.
Any way, this is one of the MANY topics that can be discussed to death but my 2cents is an opinion based on many years of experience and until a suitable justification for me changing my thinking comes along...... It's OCC for me