First of all, the Note 3 supports rSAP out of the box. My app will most probably not make any difference.
Your Audi at least supports the "Handsfree" profile, which is built into every Android phone. You need a special option in your Audi to have rSAP, it's called "Audi carphone" or "Audi connect" or "Bluetooth high" or whatever. A rule of thumb: if you don't have a SIM slot somewhere in the dashboard, your Audi does not support rSAP.
If you still want to run my app, you need to "root" your phone. Search the I how to do that with your Note 3.