To ensure **good visibility** while driving, it is important that the vehicle's windows are clean and unobstructed. However, it is allowed to place **sunshades** on the rear windows of the vehicle under certain conditions.

- **Sunshades and visibility:** Sunshades can help protect from the sun, but they must not impede the necessary visibility to drive safely.

- **Necessary mirrors:** To use sunshades on the rear windows, the vehicle must have an **exterior rearview mirror on each side** (right and left). This ensures that the driver can adequately see what is happening around the vehicle, even if the sunshades limit visibility through the rear windows.

- **Regulations:** It is not allowed to place films or stickers on the windows that reduce visibility, nor to use non-approved colored windows. However, sunshades are an exception if the mentioned conditions are met.

Therefore, the placement of sunshades is allowed as long as the vehicle has the necessary exterior mirrors to maintain adequate visibility.