Audi’s most opulent model comes in two versions: regular or stretched. Its drivetrain is comprised of a 372-hp 4.2L V8 and 8-speed Tiptronic automatic transmission. It goes without saying that the A8’s cabin is one of the most luxurious on the market. The S8 is scheduled for release in coming months and will feature Audi’s priciest engine, the W12. It is one of the best in this category.