I watched some videos of other Vantages with BT installed and typically the aux is disc 5 or 6 on the changer. I have tried the cd changer with no luck. Anyone have suggestions on how this unit may work?
Thanks

 

Does the unit show a model number?

 

It is a Fosgate RFBTAUX basically hooks into the system with rca jacks

 

I found some more information. I pulled this from behind the dash. I looks like it is a Most-AUX for Aston
Getting closer but I still can't figure out how it works.
I think I need to look for a toggle switch somewhere

The NAV-TV MOST-AUX for Aston is a M.O.S.T. fiber optic interface that introduces audio into select fiber-equipped Aston Martin vehicles with no degradation in sound quality. AUX audio is triggered with an external toggle switch (not included). Unlike cheap FM-based modules that transmit sound via an FM station, the MOST-AUX interfaces directly into the OEM fiber system and is designed to work specifically with a compatible Aston Martin vehicle.

 

THIS looks like it: https://navtv.com/products/NTV-KIT143/most-aux-for-aston.html?srsltid=AfmBOooj81g40ACGFKrYUwwYe1YUUCb AiW2IxbNneP4EOvEMIQ_dBk76
The manual is available on the website.

 

Nice, It looks like it is all correct.
t should be linking up to the disc player, disc #6 as aux. I am going to go through all the wiring and see why it isn't working.