Jack88

It just was, in America for the 2015 MY, and in Europe for the 2014 MY. I would presume it has another 2, maybe 3 years left. I would expect the new model to be debuted in America as a 2018 or 2019 MY.

MP4.2+6.0

Based on prior patterns and general consensus going forward, expect a full year 2016 run, and a short 2017 run only, which will basically be 2016 spec but with a 2017 model year designation. D5's would be 2018's in North America, probably released in Spring 2017 if it follows prior patterns. In Europe, 2016 would be the last year of the D4's and the 2017's would be D5's, probably delivered 3-6 months before they are delivered here. Also, if they follow the D3 pattern, they may cut off the low volume variants like S8 and W12 next Spring (toward end of 2016 run), and produce none in 2017 for North America; might be true for SWB (3.0T) too.

In plain English, expect D5 to be available for delivery in North America in approx 24 months/2 years from now, expect it months earlier in Europe, and expect the intro/announcement before that. Maybe expect decent spy pictures in the magazines in the next 12 months as a guess?

If you want to speculate what the gadget/electronics stuff will be, the just being released Q7 is probably the best current proxy for their larger platform upper scale vehicles, and are another step beyond the facelift D4 and just updated "2016" A6/S6 (C7) and A7/S7 models.

They also announced several months ago now the next generation specs and general changes for both the higher and lower powered/tuned 3.0 TDI, and just announced the parameters of the next W12 motors. On W12's expect turbo's on all (not just the Bentley's) and back to 6.0, now 6.0T. I haven't seen any info on changes to 4.0T, but you can guess continued power massaging, and 2016's are going up another notch to 450HP. Bigger TDI like 4.2 successor would be of interest to North America but who knows, and you can kind of guess a plug in hybrid from either 3.0 TDI or FSI. 3.0 FSI flavor is already easily found if you just look at the Cayenne now plug in Hybrid, which is an Audi quattro drivetrain despite Porsche's best efforts to overlook that (also true of the TDI's). Audi's newest press basically hints toward plug in TDI's as their next step.

Meantime, to whet appetite (from a recent German language article here: Neuer Audi A8 D5 (2016/2017): Audis neue Oberklasse - autobild.de )