Motor Authority[1] (20 November 2019): "Audi's new RS Q8 made its world debut on Wednesday at the Los Angeles Auto Show"; Carbuyer[4] and evo[5] of the same day agree and Wikipedia[2] gives November 2019.
Audi gave the RS Q8 its world debut at the Los Angeles Auto Show on 20 November 2019: a 4.0-litre twin-turbo mild-hybrid V8 with 600 PS and 800 Nm, 0-62 mph in 3.8 seconds, four-wheel steering and a German price from EUR 127,000.
€127K