INFINITI has revealed what it terms “the next step” in its design language at the Detroit Auto Show today, whipping the covers off its sleek and attractive Q Inspiration Concept – a car which it also says is a concrete preview of the next generation of production cars.

There are, of course, elements that are definitely not going to be seen at the end of the Infiniti production line. Things like the Eames-inspired seats and full-length glass roof, for example, plus those suicide rear doors – a show-car staple that nearly always gets nixed.

And the Q Inspiration lights the way, with taut, stretched sheet-metal linking the wheel arches, and plenty of adventurous venting around the front wheel wells, lower bumper and bonnet – the latter of which neatly disguises the bonnet shutline. Its fastback four-door design is overtly sporty while still remaining elegant.

Around the back, thin tail-lamp slits are linked by a thin chrome bar to emphasise the car’s width, and though the absence of exhaust outlets suggests this thing is electric, Infiniti says a version of its variable compression ‘VC-Turbo’ engine, already set to power the next-gen QX50 SUV, lurks under the Q Inspiration’s bonnet.

With Infiniti billing it as a mid-size sedan, the Q Inspiration could form the basis for the Q50’s replacement. First going on sale in in 2013, the present-generation Q50 will reach the end of its lifespan at the end of this decade, by which time an all-new model will be ready to grab the baton, and the Q Inspiration may just be a sign of what’s to come.