For the people have swapped their cdr23 with fibre optic

[Fintro11]

I will be ordering the continental radio https://www.bergvillfx.com/index.php/products/car-audio/continental-tr7412ub-or.html but am stuck on what path to go for the fiber optic cable.

I can order the adaptor from bergvillfx that costs more than the radio and keep everything behind the head unit stock.

Or

Run wires from the head unit to the fronk, remove the amp and just run the speakers off the head unit. The conti is 45w and 4 ohm. The door speakers are 75 w and 2 ohm? So I think that would fry the head unit? Unless I ran a resistor?

Or

Run wires to a new amp

I am trying to keep costs down on this project as I rarely listen to the radio while driving and mostly want this for stock look, USB / Bluetooth.

Let me know what way you guys hooked it up / what amp etc you went with.