Insurance expert Thatcham, which sets ratings for the industry, has introduced a standard requiring the devices not to work at distances of more than 10cm from the vehicle. But consultants at security firm SBD tested keys for nine cars - and only the Micra's was effective. Some still operated from nearly two feet away. This means in extreme cases, thieves could enter and start a vehicle while the owner is loading the boot or filling up with fuel.
Smart keys work by sending an electronic signal to the car at the press of a button on the fob. SBD boss David Bell said: "Tests show many of the systems don't meet the new security level that will be demanded by insurers."
The new Thatcham smart key standard will only apply to cars designed after May 2005. Those that don't meet it could be placed in a higher insurance group.
See page 20 of this week's issue for the results of the Thatcham tests