There’s a lot of discussion on the various Skoda,VW and Audi forums about the quality with some saying it’s great, some not much of an improvement over the standard system and others saying it’s really poor. As an audio engineer in a past life, I worked for NEAL Ferrograph, I know what a decent system should sound like. I’ve had upgraded systems in previous cars and this is not one of the better ones. Fitting a subwoofer inside a plastic box, then burying it in a close fitting metal well with nowhere for the sound to escape and covering it with a thick sound deadening polystyrene box and a boot mat is a really bad design. Putting it in one of the side recess’s in the boot or under a seat would give it a much better chance of being heard. Even on +9 the front door speakers almost completely drown it out.
Are you any further on the refund/compensation?
it does seem silly to bury the sub away with sound deadening materials around the enclosure.