Walk into an Audi dealership, ask for the most expensive ride and your salesperson, suddenly bursting with overwhelming friendliness, ushers you over to a shiny long wheelbase A8 with the W12 engine. At about $120,000, it may indeed be the priciest model (until the R8 supercar arrives), but you think it's a bit too long, and not quite sporty enough. Then, something with an S badge catches your eye – it's nearly identical, but a bit shorter and sportier. Plus, with its $94,420 base price (including $720 destination charge and $1,700 gas guzzler tax), you can be confident that you've selected the second most expensive car in the joint.