The new top of the line Audi A8 certainly doesn’t scrimp on grandiose luxo-appointments. Sitting behind the wheel, as much fine leather and burled walnut surrounds you as if a blue-ribbon Holstein foddered on birds’-eye-grain riflestocks had gulped you down. The engine compartment decor masks any hint of machinery within: virtually no nuts or bolts, nor wires or fluid lines. Only the various filler caps and the dipstick handle suggest internal combustion under all that plastic upholstery.