2020 Kia Stinger — coolant is old by age but mileage is low

Start with the test that can prove you wrong. Loaded-suspension checks on the 2020 Kia Stinger catch play that a wheels-hanging inspection misses. You'll know quickly if you're on the wrong tree. This is from a 2020 Kia Stinger in Orange County with 13,500 miles. That's the whole play. Your commute and mine probably aren't the same, but the test still applies. No warning lights, which is why I'm documenting it.

Update: the cheap test changed the symptom, so I'm not throwing parts yet. I'd rather pay for diagnosis than a second guess-repair.

This is usually cheaper to test than to guess. Get a real battery/charging test on the 2020 Kia Stinger, not just resting voltage, before blaming a module. You'll know quickly if you're on the wrong tree. Verbal 'we'll take care of it' is not a plan. Parking it somewhere I can hear it better next time.

I wouldn't throw parts yet. Capture voltage while the 2020 Kia Stinger is actually failing — after it restarts you've lost the clue. Save the big job until that test fails. Any freeze-frame data saved? Trying not to diagnose from the couch.

I went back under the 2020 Kia Stinger and it only happens after a heat soak, not on a cold start. Not driving it hard until I know more.