Car radio malfunction

[Ryxwaer]

I have car radio with android 6. When I turn the car off radio screen goes black and speakers are turned off too. But inside of the radio spotify keeps playing. I know it because when I have turned it off for one minute and I turn it back on the song is exactly one minute further. 

So when I leave my car for night it will deplete much of my internet data. Is there some option for automatic stopping the spotify? I had several music players installed on this radio but I had this issue only with the spotify. I am looking forwards to hearing from you. Sorry for my bad english.