Did we just discuss over email?
There are some OBD2 Bluetooth adapters that do not show as they would support serial communications. On that case RealDash assumes that it is a BLE (Bluetooth Low Energy) device. You can try to tick the ‘Disable BLE’ option in connection settings where you select the Bluetooth device. If you are serious about tweaking your car, I’d recommend that you get a high quality OBD2 adapter:
What Adapter shoud I use? - Connectivity / OBD2 - RealDash Forum