As Q8Y said,There is no deffirence bro just speedo is KM here & MILES in the U.S & this can be changed by a press of a bottun
2012 ZL1 A6
Forged 376 CI, LSA HeartBeat, Mast Medium Bore Heads & JDP ZLR Cam, ARH LT , MagnaFlow Resonated X Pipe Muffler, SW Retro Chambered + BlackHeart AxelBack, ADM 102mm Snout, JLT intake, NW 102mm TB, ID850, AGP Dual Fuel Pump, MSD Wire's, Denso Plugs, Moroso CC.
D3 Reservoir, Alky Control, FIICHILLER.
2015 Rear Fascia Conversion, Z/28 Side Skirts, Flares, Spoiler & Diffuser , ACS Quarter Ports, ShowStopper's Side Marker's, LightWurkz Halo's.
Sosche With KenWood, SLP pod with PLX guage, DashLogic .