How to troubleshoot a faulty brake in an Audi A2?

I recently noticed that the brakes on my Audi A2 seem to be malfunctioning. They feel spongy and do not respond as quickly as they used to. What could be causing this issue and what steps can I take to fix it?

The most common cause of spongy brakes in an Audi A2 is air in the brake lines. You can try bleeding the brakes to remove any air bubbles, but if that doesn't work, it's best to bring it to a professional mechanic.

Another reason for spongy brakes could be worn out brake pads. Check for any visible wear and tear, and if needed, replace them with high-quality pads for better performance.