Very casual, but I had a family connection with the owners of the company. Even still, the interview process for interns is usually pretty simple. They are definitely one of those companies who wants understand that we're all just trying to get experience and they're happy to help. You'll find yourself doing way more than you thought you would.
It also helps if you can talk cars, even if you're a girl and you don't know much, they're all gear heads and they'll light up if you can tell the difference between a Maserati and a Lambo.