No, Android Auto cannot be used solely via Bluetooth. Android Auto requires a physical connection between your Android device and your car's infotainment system to function properly. Initially, Android Auto only supported a wired connection using a USB cable.
However, in recent years, wireless Android Auto has been introduced, allowing you to use Android Auto without a physical cable. But even in wireless mode, Bluetooth is used for certain functions, such as call audio, media streaming, and some control inputs. Bluetooth is used in conjunction with a Wi-Fi connection to establish the wireless connection between your Android device and your car's head unit.
If you're interested in using Android Auto Wirelessly, consider an AAWireless device for your car. You can find it on our webshop (Europe) or on platforms like Amazon (UK & US). However, please note that it is recommended to verify the compatibility of AAWireless with your car before making a purchase.