First post in quite a while, apologies for this, gents!

Having had the car for a year, I am satisfied I'll be keeping it long term. Therefore, I wish to improve the audio a bit.

I don't want to spend much, I already have a Sony amplifier with built in crossover which will power both a subwoofer and the door speakers in the front. It does have high level inputs, but I would prefer to use pre outputs, if possible.

From looking at this wiring diagram...

It would seem that the headunit's FAKRA set of connection pins has a monaural subwoofer output, using pins 4 and 10 of the C bank of pins. Can anyone confirm that this output does work? I am aware that there is no built in crossover or level attenuation for a subwoofer channel from looking at the setup menus, but having an unamplified output will be far easier for me to work with rather than having to splice into the speaker wires.

Of course, the other option is to buy the hardware to fit an after market stereo, but I enjoy having the (albeit, outdated) satnav built into the car, the bluetooth always works well too, so I see little point in changing it.

The end result is simply to have the front doors externally amplified and have a subwoofer (whether it be the big box one currently sitting in my loft, or 2 small under the seat cabinets to save space) - this will mean if I do decide to upgrade my door speakers, I can get some nice ones without worrying about them being damaged through clipping.

Anyone?