Light and parking are all you need.
I would not go in the evening unless I was with a group.
Parking lots are closed but no one is going to stop you. You often see people hiking with flashlights.
The park officially closes at sunset and afterwards, you may run the risk of a parking ticket which is typical.
No. The park is closed at sunset. But if you park in the neighborhood to the North you can access the North Summit.
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