It's in the parking lots on the side right by the Cheesecake Factory/McDonald's. Pretty impossible to miss. Usually well over 1000 cars there, fewer if it's raining. Awesome mix as well.
Caffeine & Octane | Automotive Lifestyle & Events

There's the website if you're interested in seeing some more about it. "Starts" at 8 but as usual, people get there much earlier.