The one that says "Best Settings (HIGH, 60FPS lock)". It's just the "HIGH" Preset with a 60FPS lock in the Steam Deck menu. I am sure you can squeeze more out of the deck but I think the "HIGH" Preset looks and plays well.
You have any issue where the game was stuck at the loading screen ? Tried reinstalling and resetting my deck to factory and carx gets stuck on the loading screen