@Marian17102024: While connected to your car via Bluetooth, is the volume low while using a specific app or feature (e.g. calls, music) or is it persistent across all apps? If you swipe from the top of the screen to the bottom and tap on 'Media output', are you able to adjust the volume of your Bluetooth connection from here?
I also recommend heading to Settings > Sounds and vibration > Volume, and making sure that each of the volume sliders is at a suitable level (Ringtone, Media, Notifications and System). While you're here, toggle on 'Use Volume buttons for media', then tap the 3 dots in the top right > Media volume limit > Off.
@Marian17102024: If you intend on listening to music via your phone while it is connected to your car, then you will need to raise the 'Media' volume slider. If you follow the steps in my previous reply, then you can do so via the Volume Up and Down buttons on the side of the phone while media is playing.
For calls, try pressing and holding the Volume up button on the side of the phone while the call is connected, as this will raise the overall call volume, and leave the volume setting as the default option for future inbound/outbound calls.
