Velcro sanding discs are commonly used for auto polishing because they offer a convenient and quick attachment system. Velcro backing allows for easy and fast swapping of sanding discs without complicated attachments or tools. The discs are typically made from high-quality abrasive material designed to remove scratches, swirls, and imperfections from car paint, leaving a smooth and flawless surface. Velcro sanding discs for auto polishing come in various sizes, grits, and types, depending on the type of surface and level of polishing required. They can be used with rotary or random orbital polishers and are a popular choice among professional detailers and DIY enthusiasts.