The code should be with the paperwork that was originally issued with the car (Possibly an Audio Manual booklet) You might be able to get it from the Main Dealer quoting the chassis+registration numbers....but the usual method is to remove the radio from the dashboard and quote the MAKE , MODEL and all the SERIAL NUMBERS. Special Extraction tools are required, but sometimes using several small screwdrivers together / bent wire or similar can work...It is fiddly though
RegWorts, May 2008