What does the headliner in a vehicle do?

The headliner in a vehicle serves primarily to cover the interior roof, providing a finished appearance and contributing to the overall aesthetic of the car's interior. It is typically made of a layer of fabric or material that is applied over insulation components, which can help insulate the cabin and improve acoustics as secondary functions. However, its main role is to serve as a visual cover for the exposed roof structure, often incorporating support for various interior elements like trim, lighting, and in some instances, housing mechanisms for features like a sunroof.

In summary, the headliner is essential as it not only enhances the vehicle's look but also plays a role in creating a comfortable and visually appealing cabin space.