The Cedar Grove area of Kings Canyon has several large car campgrounds, a visitor center, a store, ranger station, etc. If you drive the last six miles to the end of the road, that is Roads End. There are no campgrounds, but there is a wilderness permit station that is staffed at certain hours only. There are several parking lots, and the overnight parking lot has large bear boxes. If you want water, there is a river nearby.
By the way, in prime season, expect there to be a line of backpackers waiting in line early in the morning. If they don't have a permit reserved, then they take their chances of getting in on the daily quota for each trail.
When a wilderness permit is issued, the driver is given a tag to put on his car, and that way it won't look suspicious when left parked there for a time.