How early doe the parking lot fill up on a weekday since they have limited parking to 10 vehicles?

I went on a Thursday, was the first car at 6am. When I left at around 1pm there were more than 10 cars parked. Based on the number of people I saw on the trail, I would estimate if you arrive before 10am you should be able to be one of the 10 with a space.

Yes, I would get there early. Even on weekdays it will fill up fairly quickly.

I realize Sunday isn't a weekday, but when we arrived at 3ish we were the 7th car. There was also a Ranger on duty to enforce the 10 car limit. In case that helps anyone.