If you want to get a spot up front to show your car, then you should be there by 4:00. We have tried to save spaces in the past, but that usually doesn't last past 5. They get really uppity. But you can show up later if you don't mind parking in the back. We'll hang out for a while, have dinner, listen to the awards, and then have some more Tesla Time. We're usually the last ones to leave around 8:00.
Edit: it costs $5 to show your car, but makes you eligible for plastic trophies and crap prizes!