You need to explain more clearly what it is you are doing.
Are you saying that you have a blue tooth connection to a radio in your car that is not an aftermarket addition? If its part of your car, then its likely down to the way that manufacturer's device is expecting the stream or audio data to be sent.
On my car stereo, if I want to play an MP3 CD, I have to put MP3's in to folders, the folders are names 0001, 0002 and so on, then in there theirs the files 0001.mp3, 0002.mp3 and so on, so you have to mess around renaming all the files because like most things, manufacturers cutting corners to shave a fer cents off a component ot three to increase their overall profits by a sizeable margin.
So I would check your manual for your device. You may not be providing the stream in a format that the player likes, I know my CD player in my car is funny with displaying track names despite setting the CD Text, it comes out looking more like Welsh or Gaelic language.
So can you help other help you by first troubleshooting this issue from the car device to your mobile device and also an example of a URL, simply saying you bave ABC and you turn it in to XYZ ABC is not very descriptive or informative, people need to see what you have done and you may be surprised that most code errors are because the coder has done something wrong and we get posts like this one popping up until its found out they are using something like JQuery and thats where the problem is and they are in the wrong forum...