[Android][Connect] Car Mode with non-integrated BT

[akumako17]

My car does not have BT built in. I do however have a BT device that I can connect my phone to that I use to play music. In the app I have Car Mode selected to use that mode "Only in a car" BUT how does it know when I am in a car if I am not using a car to connect. Is it possible to trigger that based off of my BT device? I have a Roav Bolt that allows me to use BT in my care through the aux jack.