Car camping for me means making enough room in my Jeep Cherokee to sleep in it. Because I'm travelling in the Jeep I can carry a lot more stuff and heavier than if backpacking.

I can move locations daily if desired (4WD trails) and don't have to be very picky about finding level rock-free ground for the night.

It makes a sturdier shelter for snow,hail, windstorms.
2 trips ago I was sound asleep and comfortable while my buddies were blown out of their tents by a t-storm (that also produced a tornado within a few miles). One spent the night in the cab of his pickup, the other I think spent the night in the outhouse......