The subject of theft is an easy one to comment on. The absolute truth is as follows: If someone wants anything out of your car they can take it, it takes a pro theif about 60 seconds to break into your car and remove the stereo. Secret codes and access things mean nothing to a theif, if they see something that looks expensive they are goign to take it. The only absolute way to make the unit theft proof is to take it out of your car when you park. Its amazing but stereos are stolen even if the removable face plate is not there because it is worth money to the theif. The best thing to do is to add the unit to your auto insurance policy which adds about 4 or 4 dollars a month.