I have a vested interested in making car camping as easy and comfortable as possible:

If I am going alone with my son, I have to ensure I am able to handle the whole trip solo and in such a way that a 3-year-old can enjoy it. That means extra amenities and comfort items to make sure he has a fun time and that I don't lose my mind trying to keep us warm, fed, and having a good time.
If we are going as a whole family, I have to ensure I am able to handle the whole trip solo and in such a way that a 3-year-old and a 33-year-old can enjoy it. That means extra amenities and comfort items to make sure he and she have a fun time and that I don't lose my mind trying to keep us warm, fed, and having a good time.

To that end, I have put together what I consider to be a pretty decent kit for car camping. The overall kit consists of:

2 large containers that are the staple items that will always go along
A cooler that is packed per trip
And a few odds an ends their either don't fit in 1 or 2 or are trip dependent.

And it all fits in a large sedan (takes up two extra seats, leaving room for 2) or a midsize SUV (takes up one extra seat, leaving room for 3).

The Bins

There is no rhyme or reason as to what goes in which bin other than the general fit of the items. After a single trip of just throwing everything into the bins as individual items, I upgrade to bins-within-bins for better organization.

The First Bin

This bin is mostly bulky items and contains the following:

Our 4-person tent
A utility tarp (generally used as a footprint for the tent)
A hammock
A cigarette liter air pump for the air mattress when we bring it
2 pillows + 1 inflatable pillow
Coleman 2-burner gas cook stove
1 pot, 1 pan, a silicone cover, and spatula
A shoe-box bin with: hand warmers, sunscreen, bug spray, and toilet paper
A shoe-box bin with: Hot pads and drink coozies
Solar-powered rope lights (to make our campsite look special)

The Second Bin

This bin is all sub-bins and contains the following:

Not In A Bin

Tongs
Paper towels
4x roasting skewers
Brush and dust pan
Rubber mallet
Hatchet

Fire Bin

Lighter fluid
Wax fire starters
Matches
Lighters
Fuel accessories for the Coleman cook top and my lantern
Metal hook for getting the Dutch Oven off the fire when we bring it

Plates & Cutlery Bin

Plastic cutlery (assortment of forks, spoons, and knives)
Paper plates
4x Enamel plates
Plastic cups
Tin foil

Coffee Bin

Old and stale coffee grounds
Percolating coffee maker with 4 mugs
Stanley cook set
Coffee filters

Dog Bin

Leashes
Extra long cable
Bowls (food and water)
First aid kit (for humans too, it just fits here)

Utility Bin

Large Knoife!
Cordage
Carabiners for random things
Extra stakes
Odds and ends

Non Bin Items

Some items simply won't fit in a bin or are items that I do not take on every trip.

Sleeping bags and blankets: I have 4 sleeping bags that travel on an as needed basis.
Sleeping mat/mattress: I have 2 single person sleeping pads (one blow-up, one foam) as well as a full-size air mattress, which all travel on an as needed basis.
Backpacking backpack: clothes, stocking caps, gloves, sleeping bag(s)/pad(s), extra water, and some minor emergency supplies (Advil and Melatonin)
Folding chairs for as many people are going.
Large water container. 2.5 gallons seems to be more than enough for an overnight trip.
Cooler: this varies widely per trip but one staple is a few beers and some whiskey.
Coleman Lantern: takes the same fuel as the stove and I don't have to remember to charge it.

This load out has been successfully tested at multiple state parks as well as at various dispersed wilderness campsites within the Arapaho and Roosevelt National Forests.