A national breakdown service is launching a new "magic box" which will relay crucial information from members' cars to mobile mechanics before they even reach stricken vehicles.

The RAC says its RAC Advance early warning system can also act as an instant alert if the car is involved in a serious accident.

The box, which is the size of a matchbox and will be available to all RAC members during this year, will remotely communicate with the firm's base to provide diagnostic information which could potentially identify certain vehicle faults before the mechanic arrives at the scene.

It also gives crews an accurate location for the stranded motorist, acts as a record of incidents and can provide drivers with data to help their driving efficiency and keep running costs down, the RAC said.

The breakdown service said its 1,700 patrol vehicles have already been fitted with the device and more than 35,000 fleet vehicles in the UK are already using the technology.

The firm said the box can be accessed via an app on the driver's phone.

RAC technical director David Bizley said: "Offering peace of mind in a box, RAC Advance will revolutionise how we deal with our members.

"We know that some breakdowns can be avoided with a pre-emptive warning and intervention and this will significantly advance how we are able to deal with an actual breakdown or accident, reassuring our members that they are in safe hands."