Many motorists may think that the most popular additions to cars are those which up the horsepower or improve the handling.
But it appears that out of all the different Ford car parts available, it is one that actually reduces the vehicle's speed that is in highest demand.
According to Ford, the popularity of its Adjustable Speed Limiter system has exploded since it was first introduced in 2010.
The device allows drivers to set a top speed limit for their car of anywhere between 10mph and the legal limit.
Exceeding the limit results in a reduction of the fuel supply to the engine, causing the car to slowdown and allowing the driver to remain safe and within the law.
More than 220,000 Ford cars equipped with the speed limiter were sold in 2011, making it the most popular driver aid the manufacturer offers.
Ford believes it is the knowledge that they cannot get caught out by speed cameras that makes the technology so popular with drivers.
It points out that there are now more than 35,000 speed cameras throughout Europe, with one in five motorists in the UK being caught out by the devices since 1996.
"It only takes a momentary lapse of concentration to exceed the speed limit which is why the Ford Adjustable Speed Limiter technology gives drivers so much peace of mind," said Dr Torsten Wey, technology supervisor at Ford of Europe.
The system is now available on the vast majority of Ford models, including the Galaxy, Focus, C-MAX and Grand C-MAX, and was fitted on 20 per cent of the manufacturer's cars sold in the UK last year.
Drivers can adjust the speed limit of the car in increments of 3mph and, if they need to overtake a vehicle, can temporarily override the system by pressing down firmly on the accelerator.