Drop your last sentence, and I'll give you a "Winner" award. I could have written the rest, including your age (well, in a couple of weeks).
I have a different view of "how the Stinger is doing" market-wise. I think Gregory Guillaume et al. wish for greater sales: "we" always want more sales, can't get enough of those.

But, the Stinger met 2018 sales expectations and slightly exceeded them. The market, especially for sedans, took another hit in 2019: the Stinger did comparatively well. How Kia markets the car is the arguable part: I think that they spend as little on advertising as necessary to accomplish the attention getting, and validating, that the Stinger gets. Kia has produced an amazing car: it does everything that Kia designed it to do, and at a competitive price point that blows the competition away. Then, right after that, they come out with the
Telluride, which is backordered months. The
Telluride attracts mass attention, where the Stinger attracted car enthusiast attention and obtained accolades (which continue to multiply). And that attention returns to the Stinger in process of time. Anyone who buys a
Telluride is going to know about the Stinger, from the getgo in most cases. The quality, price point, original concept of the Stinger then rebounds to the
Telluride; and any owners of that vehicle is going to be even more proud that their ride comes from the same company that produces this very highly rated, high performance sedan.