Depends on the car audio. I spent a week trying to do the opposite - hook up an Alcatel Go to a Lexus. All it wanted was the audio.
The service rep from Lexus spent an hour trying, and he couldn't do it, either. The Go is a flip phone on a postpaid account.
The previous Alcatel Island had no problems.
I even took the one MP3 the Vulcan had off the phone's memory card. Nothing worked.
Just for grins, I hooked up my Oneplus 5. Told the car system to ignore audio and it did. The Go being a flip, there is no way to program it. The OP5 did have the means on the phone itself to shut off music.
Just got the Vulcan a refurb Samsung Rugby 4, It works on our carrier, has more commands and preferences than the Go, so we'll see if I can hook that up.
Maybe in your case, you can delete the phone itself from the car audio if you don't call in the car. I paired a Moto Xpre and all the car saw was the SD car with audio. Never even asked for phone.
Will try with a Samsung Rugby. It seems to have more preferences and commands on the phone.
I am not impressed with Alcatel. It might be the actual phone with the problem. Someone complained to Alcatel and got the answer "It's a flip phone. Deal with it."