I had a similar issue with Spotify and my phone when it came to charging and Bluetooth. But I recently discovered some hidden gems about Spotify that might help you out! I found this website
streamingfamous.com that, has some great tips and tricks for getting the most out of your Spotify experience.
As for your issue, I found that instead of plugging the charge cord into the car USB port to charge, I plug it into the cigarette lighter outlet to get the charge power. This prevents the car from trying to pull data via a USB port and only pulls the data via Bluetooth. Which eliminates the annoying "no music found" message.