The Sonax brush is quite good. It cleaned wherever it was needed without any problems. The only time it didn't perform as expected was when I used it with Armor All Carpet & Seat Foam Cleaner, as it didn't remove summer stains such as sweat and saltwater from the seat upholstery. However, I believe that the brush is not to blame, but rather the Sonax cleaner.

Very good brush, used with Autoglym products. Cleaned the interior extremely well without much effort. Just be careful with the pressure on any leather scratches, although I didn't encounter any issues.

Application with Auto Glym Interior Shampoo. Powerful without causing damage (even to the sky).

Update: After the second use, the fibers in the perimeter started to go awry.