Although there's an increase in small-car sales worldwide, rising obesity levels mean that carmakers are having to go to elaborate lengths to accommodate supersized drivers.

Mercedes-Benz is testing stronger versions of the grab handles positioned above doors, so they can cope with the extra weight of heavier drivers and passengers hauling themselves out of their seats.

Ford has increased the size of dashboard buttons so that drivers with large "sausage" fingers don't accidentally press several at once. And many manufacturers now offer electrically powered steering wheels that lift away from the driver when the engine is turned off, to aid an easier getaway.

Manufacturers are taking a scientific approach to the problem, too. BMW has recruited a group of 800 "guinea pigs" to study mobility in a car's cabin - to help it ensure its models can fit 95 per cent of body sizes.


The firm has developed seats with "comfort adjusters", adjustable side bolsters that will grip thinner occupants and still be comfortable for larger ones.

Ford and Nissan have created fat suits for their engineers to wear while developing control systems, so that buttons can be placed in convenient locations for larger drivers.

The fat suit can already claim a change to the cars - it is responsible for the movement of the hazard light button from below the steering wheel to the top of the dashboard.