The device cuts out car radios and CDs at a set distance of 200 metres, giving the message 'Warning, emergency vehicle approaching.'
It allows drivers to pull over in time to allow emergency vehicles to pass.
The Radio Licensing Authority (RLA) refuses to give it the green light on the basis that it will wreak havoc on other electrical devices.
But James (right) said: "A prototype, which was tested prior to application for a licence, worked great with no interference to computers, turnout systems, TVs or any other electrical devices, which is what the RLA claim is their main reason for not issuing a license.
Written by Staff Writer