The Mercedes R-Class combines elements of the adaptable interior of an MPV with those of a luxury saloon and sits it all on 4x4 drivetrain.

Even though it launched three years ago, its 3,000 registrations mean it’s still a rare sight on UK roads.

R-Class has niche demand, although if more prospects got their bums on its seats they might understand its appeal.

In 320CDi long-wheelbase form it is a mammoth executive carry-all. Unlike most MPVs, it’ll seat seven people comfortably and still have boot space for a pushchair and several weekend bags. Its cruising ability is endless, the drive comfortable and quiet and its handling is more estate car-like than SUV.

Its only obvious disadvantages are its bulk – more than 17ft from nose to tail – and its running costs. Emissions of 246g/km CO2 and 30.4mpg combined economy mean fairly hefty VED and fuel bills.

Nevertheless, it’s perfectly positioned for high-earning parents.

Price: £41,910

Rivals: Land Rover Discovery, VW Caravelle, Audi Q7