An investigation by sister publication CAR Magazine has revealed that eight out of 10 car radios in Britain won't work after the planned digital switchover in 2015.
The Government currently plans to turn off analogue radio in 2015, leaving cars fitted with FM stereos nothing to tune into because they can't receive the new digital broadcasts.
When the switchover finally occurs between 20 and 25 million older cars will be left without a functioning radio.
There are approximately 31 million cars on the road in the UK, few of which are fitted with digital radios - which cost around the £250 mark when specified on new cars.
According to CAR magazine approximately 4% of drivers listen to digital radio in-car, compared to over 30% at home, indicating take-up to be very slow.
The switchover is expected to cost motorists up to £1 billion to fix.
Owners can install a stereo that can receive digital broadcasts for around the £150 mark - but this can be quite involved and costly to fit. Alternatively a small dash-mounted unit could be used, costing approximately £40, which connects via an auxiliary jack, Bluetooth or USB connection.
Manufacturers will not begin fitting DAB radios as standard until 2013, meaning it would still be possible to buy a car that would be affected - so, if you're looking at a new car, remember to tick the DAB option to ensure that your radio stays working. This will also protect your car's residual values and prevent you from having to pay out again for an expensive aftermarket solution.
Satellite navigation systems, both in-built and aftermarket, will also be affected unless they support digital reception, as they receive their traffic updates via FM radio.
The on-going digital TV switchover will also continue to affect in-car TV systems if they are analogue ones that only receive the five terrestrial channels - necessitating an expensive upgrade to a factory digital tuner or the use of a potentially troublesome aftermarket unit.