I want to throw an air mattress in the back of my pickup truck and take my girlfriend to some scenic place to watch the sunrise. I'd really like to do this by a beach such as corona del mar, laguna beach, newport beach, or huntington beach. I'm unsure how the local authorities would react to us being parked at night. I want to arrive sometime in the early morning 3:00 am-ish and stay until sunrise. Suggestions?