In a couple of years time we might well remember Detroit 2012 as the show when American car styling rediscovered the fastback. Coincidentally, and as if to reinforce the message, a 1971 Ford Mustang Mach 1 took pride of place outside the main show hall at Cobo.

Of course the fastback look has been returning slowly for a couple of years, mainly in European design, helped by the increasingly long dimensions of today’s family and executive cars, which allow designers the luxury of a sweeping roofline starting at the B-pillar and terminating in a aerodynamic, ‘bustle’ boot.

The Aston Martin Rapide and Porsche Panamera feature extended, sloping rear three-quarters, and the European Mondeo and Opel Insignia have also taken advantage of generous dimensions to create the fastback look.

The Audi A5 and A7 also incorporate the theme. But two significant new designs at the show, the Ford Fusion and Toyota’s NS4 concept, the latter presented as a study for the Prius hatch, give priority to the fastback on US-focused designs.

Both have the hallmark, sloping rear glass, tapering into an abrupt ‘kamm’ tail in their overall proportions. The four-door Fusion appears to create this look at the expense of a lengthy rear overhang, although this perception of the new Mondeo may be deceptive.

Ford’s chief designer Martin Smith told me the four-door is only a few millimetres bigger all-round than the current European Mondeo. And the five-door hatch, which was revealed to a hand-picked group of Euro hacks (I wasn’t there) is actually a few millimeters shorter.

The Lincoln versions of these cars are said to be even more rakish, as previewed on the MKZ concept yesterday morning.

But Toyota’s NS4 may yet emerge to be the most significant of them all. The NS4 opens a new, more exciting chapter for Toyota design and if the fastback look is to be a key feature on future European models like the Auris and Avensis, there is hope that Toyota can lift the desirability of its models — all with the simple expedient of a sweeping roofline.