Yes, they are referred to in the industry as "MVARS" - Mobile Video Audio Recording Systems. If audio and/or video are available, they are relevant and can be subpoenaed and/or requested through the prosecutor.
As long as there is video, you'll be able to get it through the prosecutor. Whether there is video may depend on the agency that arrested you. I believe that California Highway Patrol has MVARS on all of its cars. If it's a local police agency, it will depend. I always request MVARS at arraignment on DUI cases. The video would show some portion of you driving/being pulled over, but I've found that most of the officers do the field sobriety tests out of the camera's sight. You might still be able to hear audio. I just argued at a DMV hearing, where the CHP officer had my client perform the tests out of the camera's sight, but the audio may have caught the officer in a lie.
Your attorney should be able to get that video from the prosecutor through discovery if they have one.
Nothing said here shall be construed as legal advice. I can not effectively advise about your case without knowing all the facts. Additionally, my response does not create an attorney-client relationship. If you require further assistance, please contact an attorney privately.
Yes. Your attorney should have obtained the recording by subpoena in connection with the DMV case. This gets the video much more quickly than waiting for it to be provided by the OCDA's office in supplemental discovery. If CHP arrested you, the video is called MVARS. If OCSD arrested you, it is usually called PVS or MAVS. These are all acronyms for audio/video recording system. Both CHP and OCSD have recording units in almost every patrol vehicle that is being used in south OC. If your lawyer didn't get the video in connection with the DMV APS case, maybe he was confident that the video would only hurt your case. He should have obtained the video anyway. If your current lawyer did not answer this question, you need a new lawyer. If you have a paid attorney and you feel the need to look for answers on AVVO, you desperately need a new lawyer. Your new lawyer will inform your old lawyer of the substitution so you don't have to do the firing yourself. I have cleaned up many mishandled DUI cases. The sooner you get a good lawyer, the better the outcome will be. You will also be entitled to a larger fee refund from the old lawyer if you get rid of her earlier.
Yes, any video, including the MVARS, in the possession of the government (cops and DAs) can be subpoenaed. In fact, you don't even need to subpoena it. A simple request/reminder to the prosecution should suffice to have it turned over.
You should work with your attorney on this one, but if you chose not to - you can go it alone. You can contact the arresting agency and request a copy of the MVARS video (or any other video) for the particular date, time, police vehicle in question. They should provide you with a copy (a nominal copying charge will have to be payed) with little hassle.
I'd be surprised if OCDA hasn't already turned over the video (if one actually exists) to your counsel. They're usually pretty good at complying with discovery.