IRRC Hyundai owns something like 30% of Kia but does a lot of shared engineering to reduce costs. The genesis line is, IMHO, Lexus/Infiniti were when they were introduce; i.e. a high quality car that sold for less to break into the market.
I agree. A lot will have to do with how a company is willing to partner in terms of branding, service, etc. I doubt many manufacturers would want to build separate Apple Car Stores inside a dealership; and dealers would likely balk at that as well and simply not sell Apple cars. Look at what GM is doing with Cadillac, as an example.
If Apple decides to go it alone they will run up against franchise laws in the US. Dealers are very powerful politically and would certainly view Apple as a threat and push hard to keep them out. Going with an established, but not major player, gives Apple a lot of leverage and takes away a lot of the risk and puts it on Hyundai or Kia.
I have a friend who had the same experience and as a result is a big fan and plans to put another 100k on it at a minimum. His Sonata looks like new externally and in the interior and has a new engine as well. I understand Hyundai offers a lifetime warranty on the replacement?
Hyundai's used to be the rental car you avoided and only took as a last resort or if the other option was a Suzuki. They have come a long way from those days; despite what some may say.