Convert AUX to Bluetooth Audio?

So I have a different way I setup my subwoofer into my car. I have a Chevy Volt and I did not want to take off the dashboard to connect a subwoofer as there is no dedicated subwoofer rca plug on the radio box. And I can't buy a new one because there is no place to put it. So I went ahead and took an rca to aux cord from the subwoofer amp that connects to a splitter which connects to my phone. Then the splitter also goes to my car aux input. So I have my phone splitting the aux into the subwoofer and the car radio.

Onto my question, is there any way to make this wireless? I am tired of messing with wires and want to somehow make the aux bluetooth. I know there are tons of bluetooth recievers but they are all bluetooth to male aux. Can I just use one of of those then convert it to female aux?

Has anyone done anything like this?

Thank you.