Mercedes-Benz R-Class

The poor Merc R-Class has always suffered from a bit of an identity crisis. SUV? Wagon? MPV? Crossover? Charitably, Mercedes has tried to resolve the R's woes by transforming the big six-seater into a big seven-seater. And a big five-seater. With two-wheel drive. And four-wheel drive. That'll help, then.

Aiming to muscle in on the sales of the Audi Q7 et al., Merc has squeezed an extra seat into the R's second row, creating a regular seven-seater. Only it's not quite that simple.

The entry-level R280 CDI here sits on a slightly shorter wheelbase, with just one row of three seats in the back. So you get a whacking great boot to stash all of your emotional baggage, but rear passenger legroom is less generous than the R's still-hefty footprint would suggest.

It remains a great wallowing beast on the road too; the R280's diesel engine - a detuned version of the 3.0-litre V6 in the R320 - struggles with the sheer bulk of the car. It's a problem that's compounded by the absurdly lazy seven-speed auto. Delayed kickdown? You'll need a diary to plan your overtaking manoeuvres.

Unlike the rest of the range, the R280 is rear-wheel drive only. Unless you're planning a spot of impromptu tobogganing, you'll barely notice, but it doesn't help to allay the sense that the R-Class doesn't know what it wants to be. Amazingly, Mercedes has managed to make the world's most schizophrenic car yet more confusing. A lifetime of expensive therapy awaits the R, we fear.

Sam Philip