I can pair my new iPhone 11 to my car but I’m not able to play my music on my car stereo.

Hello Panda789,

Thank you for using Apple Support Communities! I understand that you're able to pair your iPhone 11 to your car stereo, however you're unable to play music. I would be happy to help point you towards a resolution.

I would like to start by ensuring that you've updated your iPhone to iOS 13.1.3:

Update your iPhone, iPad, or iPod touch - Apple Support

Here's the different ways you can connect your iPhone to your car stereo to play music:

Play music, podcasts, and audiobooks in your car - Apple Support

Looking at the "Before you start driving" section, could you tell us which option you're using to connect your iPhone to your car stereo? What happens when you try to play music? If you encounter an error, what does it say?

Cheers!