The following information was distributed on the Miata mailing list, and created quite an uproar there. If you are a thief and have been frustrated in your attempts to use all those Miata radios you stole, this information will likely be valuable to you. If you're an honest person with an unscrupulous dealer who wants you to replace the radio just because you forgot the code, it will be extremely valuable to you.
Without further ado:
Performance Buyer's Club
>For most 1995 & later Miatas - > >1) Press "Track/Tune/Rew/FF" Button (side with the symbol V) >2) Press the "FM 1/2" button >3) Press the "Auto Memo" button >4) Press the "Tape" button > This should give you the "- - - -" >5) Using preset buttons (1-4) Enter the code "5011" >6) Simultaneously press "Track/Tune/Rew/FF" Button (side with the symbol V) > andthe "Auto Memo" buttons and hold. >7) The display should read "Good"Return to my home page