The Milltek
Cupra/Bocanegra system has only the single rear silencer regardless of whether you have the cat-back system or the full turbo back..there is no option of resonated or non-resonated.
The OE system on initial development recorded a sound level of approx 79-80db.
The Milltek Sport cat-back system recorded a sound level of approx 84-85db
The TBE recorded a sound level of approx 88-89db
The main design brief for this vehicle was to develop a system that was track day friendly, had a deeper than stock tone with limited to no intrusion inside the vehicle when crusing and sound sporty and aggresive on wide open throttle..from driving the development vehicle I can say this was acheived quite well.
As per one of my previous posts the system is designed for performance rather than being loud and intrusive/annoying.
Hope this helps