DETROIT – Audi AG hints strongly at its long-rumored, coupe-like A7 4-door sedan to come with the unveiling of the Sportback concept at the North American International Auto Show here.

As its name implies, the Sportback is no sedan, however. Its more wagon-like profile suggests the A7 lineup may extend beyond just a single body style, with the 4-door coupe targeted more at the sedan-centric U.S. market and the Sportback earmarked for Europe, where wagons have greater appeal.

The first glimpse of the A7 sedan in full production dress could come this fall at the Frankfurt auto show, Audi insiders suggest.

Until then, the Sportback provides the best look yet at the lineup-expanding A7.

Based on Audi’s Modular Longitudinal architecture that spawned the A5/S5, A4 and Q5, the 5-door Sportback measures 194.9 ins. (495.0 cm) long, 76.0 ins. (193.0 cm) wide and 55.1 ins. (140.0 cm) in height.

That makes the concept more than 14 ins. (35.6 cm) longer and 6 ins. (15.2 cm) wider than the A4 Avant and roughly 10 ins. (25.4 cm) lower in profile than the Q5 cross/utility vehicle.

Audi says the show car indicates a determination to broaden its Sportback lineup, which for now consists of the 3-door A3 and upcoming smaller A1 Sportback that was unveiled in concept form at the Paris auto show in October.

Under the hood of the show car is Audi’s 3L 6-cyl. TDI diesel that will hit U.S. shores this year in the Q7 CUV. As in that model, the engine is rated at 225 hp and 406 lb.-ft. (550 Nm) of torque in the Sportback concept.

Power is driven to all four corners via Audi’s 8-speed tiptronic transmission and quattro full-time all-wheel-drive system.

Weighing in at 3,968 lbs. (1,800 kg) and boasting a fairly slick 0.30 drag coefficient, the Sportback will hit 62 mph (100 km/h) from a dead stop in less than 7 seconds and reach a top speed of 152 mph (245 km/h), Audi says. Fuel economy is expected to average 37 mpg (6.4 L/100 km) based on European test cycles.

Exterior design picks up cues from other Audis. Rear styling and the strong, horizontal shoulder line that helps plant the vehicle on the road are borrowed from the A5. The car’s single-frame grille first appeared on the A1 Sportback concept. The large glass roof is a feature offered on the Q5.

Inside, leather abounds from the headliner, instrument panel, doors and seats and on through to the cargo area. Oak trim, featuring a horizontal pattern of light and dark lines, adorns the IP, center console and doors.

Cargo room totals 17.7 cu.-ft. (500 L).