One of the highlights of every motor show is the concepts: those one-of-a-kind dream machines that most of us will never be able to buy or drive. At this year's show in Detroit, those dreams were a bit less vivid, with more down-to-earth and less flashy cars outnumbering the more radical and glitzy ones.

Carmakers create concepts to try out ideas for the cars of the future, and find out what people think of them.

In the case of cars like the Mitsubishi Prototype X (which is, more or less, the new Evo 10), and the Chevrolet Camaro convertible, that’s the very near future―these cars will soon be pouring out of the factories. Showing concept like these can generate buzz around an upcoming product even if a finalized, ready-to-roll car isn't available. Carmakers also like to double-check that potential buyers like way a model is stacking up before it's too late to make changes. 

Naturally, concepts give a glimpse into the very distant future of vehicles that usually seem to be the most fun. Unrestrained by the limits of today's technology, designers love letting their imaginations run wild. But this year, designers have been kept on a tight leash―probably because so many manufacturers cannot afford to make anything too extravagant.

Only the Nissan Bevel and Ford Airstream are truly new and radical. GM’s retro-chic Holden Efigy is new to the U.S. but has been seen before, and the Chevrolet Volt, despite its futuristic propulsion system, is otherwise rather conventional.

Close But No Cigar

So most of this year’s concepts fall into the middle ground. They point the way to future models, but aren't yet ready for the assembly lines. Fundamentally they're working vehicles, but often include a few features that are over-the-top than suitable.

The Ford Interceptor, for instance, is built on a Mustang chassis and the exterior and drivetrain wouldn’t need much taming before reaching the showroom. It’s unlikely, though, that the square steering wheel, belt-leather seats, or headrests that deploy from the roof will go into production.

The Chrysler Nassau concept also looks like a work in progress, and Acura is very candid about the fact that the Acura Advanced Sports Car concept is likely to become the NSX's replacement. You only need see the name of the Honda Accord Coupe Concept to understand that it’s a concrete plan. And Jaguar’s C-XF will lead to an eventual S-TYPE replacement.

It’s less certain that cars based directly on the Lincoln MKR, Jeep Trailhawk, Mercedes-Benz Ocean Drive or Kia Kue concepts will get the green light. Although they are more speculative, these last cars are at least serious proposals.

There’s a telling postscript to this story of relative austerity, in the form of the Changfeng Motor Company. The Chinese company's far-reaching ambition, and its daft three-axle Rhombic concept, are a marked contrast to the restrained mood in evidence almost everywhere else.