Reddit mentions of August MR220 Bluetooth Audio Receiver for Sound Systems - Plug & Play your Music Wirelessly from any Bluetooth Device onto your Car Stereo, Home Stereo, or Portable Speakers (White)

same thing 1/2 the price

amazon Just bought this. Clear sound. Affordable. Easy to connect.

Awesome, thanks! And... one final thing? :)

I came across a pretty cheap bluetooth thinger, and was thinking of integrating it. If I think I know what I think you've taught me then I think I have it setup right in my diagram... if you wouldn't mind to let me know right/wrong or what to change/improve?

Here's the diagram with bluetooth

I added a switch so the bluetooth power can be turned on/off from the battery to help save and conserve battery power when unplugged.

Here's the bluetooth

Here's the Voltage Regulator - I was just going to get the same one as the speaker amp uses since it's adjustable.

What do you think? Should that be fine? Or is there anything I need to change/add? Any diode's anywhere or anything?