| Concept Car Review | LA Auto Show 2007 | Audi Cross Cabriolet quattro concept |

LA is a sunny place, so an open-topped version of the forthcoming Audi Q5 may make sense there, but most of the rest of the world has no need for such a thing, so you can probably ignore that aspect of the Cross Cabriolet quattro concept revealed at the annual Los Angeles Auto Show this week, but otherwise, the latest show car clearly points to next year's compact SUV.

Perhaps just as significant to the US market though is the display of a version of Audi's 3.0-litre V6 TDI engine that the company is claiming to be 'the world's cleanest diesel engine'. Along with the usual array of technology (including common rail injection with piezo crystal technology and exhaust gas recirculation), the concept features an after treatment system that injects AdBlue into the exhaust stream, in the process reducing oxides of nitrogen by about 90%. So-equipped, the Q5 would pass even California's super-strict emissions laws.

It's no slouch either, with 237bhp and 369lb.ft of torque to distribute to the concept's four wheels. Naturally the Q5 will feature a version of Audi's quattro four-wheel drive, though the Cross Cabriolet's layout suggests that it will apportion more of its torque to the rear wheels - as the RS4 first did - in a bid to give the SUV a sportier bias. There's nothing wrong with the quoted 0-62mph in 7.2 seconds and a top speed of 149mph either, though Audi also quotes nearly 39mpg on the combined cycle.

All these numbers will pale into insignificance if the new Q5 doesn't deliver the goods where its customers demand it most, and that means in terms of styling. The new Cabriolet concept differs markedly from the earlier Cross Coupé not only by the fact that the latter has a roof, but also in the sculpting of the wheelarches and the shaping of the bumpers. It remains to be seen how much of the concepts' design will make it to the showroom. We expect to see the finished article at the Detroit Show in January.

Not so likely for production is some of the neat technology contained in the Cross Cabriolet concept, such as a satnav system that interfaces seamlessly with Google Earth and a barely noticeable intercom system that subtly amplifies passengers' voices when the roof is down so they can be heard.

Shane O' Donoghue - 14 Nov 2007