iPhone charges but can't play music in the car?

Hi all

Recently started having an issue playing music through my iPhone in the car. Connection is via a USB lightning cable, had no problems before at all. My iPhone charges once plugged in and knows it's plugged into something because no audio comes out of the iPhone speakers. However, no music comes out of my car speakers either, sometimes it doesn't even recognise the iPhone media at all and just solely charges it.

I've updated my car software (Blue&Me) to no avail thinking that was the problem, however, it appears to be the phone as I've asked a few friends to play music through my car and it worked just fine.

I read online that it may be a problem with the cable or the port on my phone. New cable had the same issue and I've recently bought a new iPhone which also doesn't work. I restored the new iPhone from my iCloud backup from the first phone I tried, however, so I'm thinking it may be a software issue stemming from that which I've now backed up onto the new device?

Sorry for the long question! Would be really grateful if anyone has any ideas on what could be causing it. I've updated my phone to the latest iOS also.

Thanks!