The next big thing is, perhaps by definition, pretty hard to figure out.

In a car industry ever hungry for new niches and new concepts, but terrified of launching a duffer, only very occasionally does something unexpected escape from the customer clinic.

Renault’s ill-fated Avantime is perhaps the best example of a niche too far, but that was an idea unique to one manufacturer. The chances of another carmaker having come up with a car like the Avantime would have been near non-existent.

So how can we explain the appearance of these three cars at the Detroit show?

The Acura ZDX, Toyota Venza and Honda Accord Crosstour look like they could have all been drawn up to the same brief. Looking like squashed SUVs that can’t decide if they’re tall estate cars or, in the case of the Japanese cars, four door coupes.

But although the Acura and Accord come under the same ownership umbrella, all were conceived separately.

The Toyota Venza was first off the production line, launching 12 months ago. The Acura ZDX appeared at the New York show in April 2009 and but the Accord Crosstour was announced in July 2009, so all were signed and sealed before the Venza became public.