Anybody know what this switch is for?

[demos]

Can someone help me identify this switch or its functionality? It's just above the gas pedal.

[Jeroen]

Fader for front/rear loudspeakers, and with its original wiring!

[demos]

Thanks! Any pic of the button I'm missing? The radio works but cassette player doesn't. Is there an elegant solution to stream.bluetooth music without destroying the classic/classy interior look?

[Jeroen]

See below, later versions came without the white print.

Most classic radios come with a DIN connector at the back allowing line in, which can easily be combined with a bluetooth adapter or adapter cable.

[demos]

Thank you Jeroen
I saw that button stashed in the drawer when I first bought the car bout a year ago. I put it somewhere so it wouldn 't get lost.
Now if I can only remember where I stored it

[Jeroen]

Hahaha happens to all of us!