hey guys
im looking for whats called a "line in adapter" for my car audio.
I want to bypass my headunit, and simply use an aux in or BT adapter to drive the speakers directly through the amp.
Ive been googling this but all i find are "output converters"

i hate my cars early 2000's ugly as fuck headunit. i only use my phone as an input device. ive seen setups were folks completely remove their headunit and have a simple volume knob with an aux input.

it kinda looks like pic related. not sure if thats what i need.