The C&C veterans have pretty much answered all of your questions.
But to suggest one good car place to visit, one that you can go to pretty much after Cars and Coffee Irvine is the Marconi Automotive Museum in Tustin, California. It has many great and rare cars like a Jaguar XJ220 S, one of Aryton Senna’s Mclaren F1 cars, a Cizeta Moroder V16T, and one of Michael Schumacher’s Ferrari F1 cars. It is also, basically, a place of charity. A lot of the proceeds go to organizations to help children in need AND you can get to see many nice cars. Plus, on Sunday, August 5th in Tustin, there’s a car event going on called the Million Dollar Breakfast cruise.
Also here’s a link to a website with a lot information on the car events happening in Southern California: