Have weird steering problem, I think. Sometimes the car seems to slip to the side, like you hit ice or water. Happens when
changing lanes or slow turns at low speed. Dealer says its, independent shop said they thought it might be steering box (is that a thing?).
Now thinking it might be more of a steering mechanism than tires (they're fine).
anyone experienced anything like before ?

 

huh? dealer says it's what? you left that out. the gs doesn't have a steering gear box. it's an electrical steering rack, it either has a pinion assist motor or rack assist motor.

 

That's likely your rear wheel steering working.