Photos, photos and more photos to illustrate your point will help. An enlargement of the area using google maps or google earth (or google street view), a prepared diagram of the area you can use on cross examination of the officer and even video (bring several copies of the video on DVD and be prepared with a portable player) will help. If you're making a video, show things from your perspective, where you say the officer was, etc. Try and avoid any narrative on the video - it's technically hearsay, so just film the video in silence and you can offer testimony at your court trial.
Don't make the video overly long and forget long, slow zooms in and out to try to emphasize your point. You'll be one of many trials set for that day, so the judge will appreciate your brevity as well as preparation. One final word about trying to introduce video evidence - try your best not to make it shaky. Nothing like having it come out like the Blair Witch Project to turn the judge off.
You may also want to invest in the Nolo guide to beating a traffic ticket in California as part of your preparation.