Bang and Olufsen upgrade
 

I have a 2015 A3 with the non Bang and Olufsen stereo. I enjoy the sound. I feel the Bang and Olufsen stereo would be even better without going with an aftermarket subwoofer and amplifier.

Assuming I can find a Bang and Olufsen system with wiring online, would it be simply plug and play or most connections not in the car stock

Or, should I simply ignore the headache and for aftermarket?

If you enjoy it as is then I would leave it alone. If it ain’t broke don’t fix it. Could turn out to be costly, problematic, and results are for sure not guaranteed.