Ok, it looks like OC has the majority of interest.
So how about here:
https://maps.google.com/maps?q=33.721831,+-117.793966
This is in the Best Buy parking lot off of Jamboree and El Camino Real. There's lots of space and it wasn't busy at all last time we did it there.
I'll update the original post with this info.
Is 10:00 still a good starting time?