You will have to remove the radio from the dashboard (using special extractors..see Ebay ) and then quote the MODEL and SERIAL NUMBERS found on the casing. VDO is a Philips model and unfortunately I don`t think that there is anyone on these Help Boards that can calculate the Philips code so try one of the "professionals" on Ebay....It won`t be free though.
RegWorts, May 2008
