Audi might have packed a lot of performance into the A8, but it's at no expense of comfort. In all A8 models, a quiet cabin, supportive seats, and a quiet ride make this one of the best long-distance vehicles on the market.
The V-8 Audi A8 comes in standard-length A8 and extended-length A8 L models; and without hesitation we'd recommend the A8 L to nearly all U.S. shoppers. With five inches of additional wheelbase and overall length--nearly all of it going to rear legroom--you get a roomier rear seat, with easier entry and exit, and no significant sacrifice in maneuverability. In the A8L models, you also get longer doors, but any inconvenience from that is also worth it. The extra length might slightly affect maneuverability a slight bit, but it's a positive for ride.
Front seats are ample and supportive, combining cushiony softness at first with an underlying firmness that should make them all-day comfortable. They have great mid-back support, combined with headrests that are supportive without forcing your neck forward. In back, while the standard backseat setup has long cushions good for lankier passengers, there's simply not enough legroom back there in the normal-length A8; so do get the A8 L unless you're tight on parking space.
The A8's cabin is a very quiet, refined place, and while you won't hear much wind or road noise, you will hear the engine somewhat during acceleration. The air suspension system also recalibrates itself to Comfort, Dynamic or Auto modes, though it rides reasonably well in all three with not a lot of discernible difference on most roads (though we did notice a slight bit more road noise in Dynamic than the others on one particularly coarse Interstate stretch).Available on the A8L (and included in all W12 versions) are lavish individual seats in back that might just be cause to get someone else to do the driving. Four-zone climate control keeps everyone comfortable, the rear seats are power-adjustable, and the right-side one includes a footrest while the left-side seat includes massage and recline functions. Also on offer in either model is a two-panel panoramic sunroof that makes the interior considerably brighter without interfering with headroom. In either case, the A8 has plenty of trunk space, and the rather long trunklid allows a wide opening.