They aren't running really old race cars, as the name would imply, just running a practice weekend for the historic cars, i.e., the historic cars that run next weekend.
Zero people show up this weekend, except for the drivers and cars.
Great time to go.
Not sure where you can get a pit pass, but it's well worth it as all the car owners are just hanging out and available for "chats."
Update: Parking is free at Laguna all this weekend, I checked.
Pit passes are $20.00 and most of the car drivers are just hanging around their cars.