Why is it when Sliding across the car seat when the car turns a sharp corner Is primarily based on newtons 1st law of motion and not 3rd law of motion? Explain in 1 sentence

Sliding across the car seat when the car turns a sharp corner is primarily based on Newton's 1st law of motion because it states that an object at rest will remain at rest unless acted upon by an external force, while the 3rd law of motion (action-reaction) focuses on the equal and opposite forces between interacting objects.