Just look at the dozens of threads dating way back in which people had to leave their cars for days on end because no parts were in stock.
A couple of weeks ago I chose random parts for random cars (Chevy, Nissan, etc) and called the dealerships to see if these random parts were in stock. The only two dealers that didn't have parts? The two Kia dealers.
My dealer didn't even have the cabin filter in stock. Basically, unless you're there for an oil change, you have to leave the car or come back in three days because that's how long it'll take for the part to arrive.
I've owned Ford, Toyota, Nissan, GM, and Infiniti prior to this car. This is the first time I've had the experience of owning a brand that has dealerships that literally carry no parts in stock. Both dealerships here admit they don't have any parts in stock at all, and order them only when needed.
So...need a cabin filter? Forget it. Brakes? Nope. Rotors? Nope. Fan belt? Nope. Battery? Nope! Need literally any part other than oil filter and oil? Forget it. You can come back in three days.
Every other dealer had each of these parts (batteries, rotors, serpentine belts, clutches, etc). Kia had none of them. Two dealerships, zero parts in stock. So, if by chance my car breaks down, it will be a minimum of three days to get it back.
First and last Kia unless they step up and make big improvements.