Just sold my 2008 QP GTS. This is by far one of the best sounding exhaust systems. Im including the Larini X=Pipe. I currently have it listed on eBay if interested Kreissieg Valvetronic Catback Exhaust 04-12 Maserati Quattroporte 4.2L and 4.7L | eBay

Fits all Maserati Quattroporte 4.2L / 4.7L models (Standard, Executive, Sport, Sport GTS)
Kreissieg is the originator of the valvetronic dual-tone exhaust system. Not only do the valves control the loudness, but the system also features a special muffler construction to produce a unique exhaust tone. This is how Kreissieg can achieve its high-pitch exhaust sound that no one else can imitate. Kreissieg stainless steel exhaust systems are offered with either titanium or stainless-steel tips.
  • Valve System for controlling loudness in two modes
  • Stainless Steel construction
  • 4x76mm Stainless, Billet
  • Electric wired remote control switch (Not included)