Well my 2019 Stinger GT has now reached 1 year old and 12,000 KM.
First service done free of charge, the following list of issues were given to the dealer with their current status after servicing.
Rain Sensor/Wiper on auto only would intermittently work then not work, wipers coming on in clear days requiring wipers to be turned off, to the opposite extreme torrential rain and wipers would not come on at all - Fixed
Throttle position sensor/transmission reluctance to shift down in comfort/eco mode unless I put my foot to the floor - Fixed.
GPS drift, driving along normal roads that have been there for years, my GPS started to drift off road - Fixed, I don't know how as I'm on the latest Map update.
Very slow startup/response from infotainment system - navigation (as in navigating settings not SatNav) is slow and is still not ideal - Not resolved yet, but new map and system update is coming soon I'm told.
Radar Cruise control even set at closest distance from car in front would leave a gap of 50 to 60 metres @ 100km/h regardless of how close I set it - Fixed.
Left rear type pressure sensor failed - Replaced and fixed.
Door lock buttons on front door handles are still a problem from day 1 - still only working 30% of the time the rest of the time it just long beeps - Not fixed but proven issue with even new 2020 GT model - Kia have been advised as it appears a common problem.
All in all the car is great, I have zero squeaks and/or rattles the car still feels new and is still highly enjoyable.
Although 75% of my driving is Melbourne CBD, and I'm not much of a hoon

the Michelin Pilot Sport tyres are stuffed, they will need to be replaced in the next 3000 Km. All my cars over the years (all high performance) I'd get 25,000 to 30,000 KM from tyres but these wont last 15,000KM. I'm not going to replace with these, they are also getting very noisy now (less tread and hard casings).
I've requested the following to Kia, and the dealer has past on my feedback, as I'm not the only GT owner asking for these things.
On startup the Infotainment system to start at the last screen configuration rather than back to default (split media and Satnav).
Option to enable Auto hold and have it on all the time.
Requested bluetooth enabled for Android
Car play as an option rather than USB cable - This will require the base Android 4 infotainment system to be upgraded, but it sounds like the infotainment system is going to get a upgrade in the next few months.
I have to give Kia a big congrats, their customer service is stellar compared to any other brand I have owned.
Cheers,