Why did the noise inside the car sound significantly louder on the durability road during the livestream?
Official answer
The proving ground roads are "deliberately designed" to create extreme operating conditions.
When testing on the reinforced road, the vehicle continuously endures extreme vibration and impact far beyond daily driving. Research data shows that when a vehicle passes over a corrugated road at a specified speed, the vertical force amplitude on a single wheel can reach up to 6806N. Under these physical conditions, significant noise inside the car is an inevitable physical process.
The roads at the proving ground are designed specifically to "torture the car." Loud noise is normal; engineers must verify whether the structure is reliable in such harsh environments.