German automaker Audi is testing a facelifted version of its A8 flagship sedan. Spy photographers captured images of the new model undergoing testing.Spy images reveal that styling changes will be minimal. In true Audi tradition the changes are likely to consist of subtle tweaks to the lights, grille and bumpers.Image galleryThe interior of the new A8 is likely to receive subtle updates, along with some new technologies including the latest version of the automaker’s internet connectivity services, a modular infotainment system and possibly a redesigned instrument cluster. It’s not clear if Audi will be planning significant updates to the engine line-up. The current 3.0 and 4.0 TFSI units should carry over as well as the range-topping 6.3 W12 engine.A 178kW 3.0 TDI diesel was just added for the 2014 model year, so this unit will almost certainly carry over with the same spec.The facelifted A8 sedan is expected to be launched in 2015.