The 2018 A5 and S5 coupe and convertible have been redesigned and go on sale this spring. The A5 gets a 252-hp, 2.0-liter turbo four-cylinder matched to a seven-speed dual-clutch automatic. The S5 is powered by a 354-hp, 3.0-liter turbo V6 mated to an eight-speed automatic. All-wheel drive is standard. The Sportback, a four-door hatchback, will also be available. Standard safety equipment includes forward-collision warning with automatic braking. The outgoing A5/S5 coupe and convertible have quiet, luxurious cabins. Although snug, the rear seat is one of the best in any convertible. The car drives well, with nimble handling and a firm yet supple ride. The convertible is almost devoid of wind buffeting, and you can operate the insulated soft top up to 30 mph.