The BBC reports that the Wirelesss Telegraphy Act of 1949 will be amended to allow for the use of FM transmitters in cars. Prior to this change, their use constituted operating a radio device without a licence. Changes go in to effect December 8, just in time for the last leg of holiday shopping.

However, many devices currently on the market will remain illegal as they do not meet the legally required technical specifications and could interfere with radio broadcasts.

The new amendments will also reflect a European standard on the low-power transmitters.

All approved transmitters will carry a CE mark indicating approval for sale in the European Union.