There are many options to consider when you build an advanced car kit:

Space – you need to consider where will you store these advanced items? Will they fit in the trunk of the vehicle without taking up too much room? Should you put everything in a plastic container to keep everything together? Do you have room for a change of clothes for each family member?
Temperature – chances are that some of the items that you put in your car may not be used for a long period of time, if ever. Thus, in cold weather or extreme hot weather, these items may deteriorate and may not be useful at all during time of need. You will either need to rotate the items that may be impacted, use them or even keep them separate from your other car items and take them out to the car when you leave the house.
Perishability – some items will become unusable over time, so it’s important that you rotate or remove these items before they perish. I am talking about food items like protein bars or emergency snacks for children, hand sanitizer, ointments in your first aid kit and emergency gas (that has been stored in a container in your trunk). To minimize perishability, put a reminder on your cell phone to check or replace some of the contents of your car kit(s) six months after you put it in your car(s) and every six months thereafter.

Here are some suggested items to add to your Basic Car Kit:

NOTE: An Advanced Car Kit should include all the items in your ‘Basic Car Kit’, plus some of these optional items:

Fire, Heat and Light Options

Flashlight – be sure to get a hand crank one, so you never have to worry about the car battery running out.
Hand warmers
Fire sticks – these light even after being submerged in water
Light sticks – stock up in the months after Halloween
Road flares and/or reflectors
Candle, matches or a lighter and empty coffee can – so you can see in the dark

Shelter and Clothing Items

Sleeping bags (if you have room)
Ponchos for each family member
A change of clothes for each family member (pack in plastic)
Coats (useful as a backup if it gets cold outside and allows you to use your car heater less to save fuel).
Extra pair of socks for each family member (more important than you think)
Spare shoes in case yours get wet or become damaged.
Umbrella(s)
Tube tent – you can buy these for less than $10.
Sewing kit
A mesh laundry bag – handy for putting dirty or soiled clothes or other items.
Extra boots, winter hat, gloves, and scarf

Vehicle, Tools and Equipment items

Convenience items

What can I add to my Basic Car Kit to make an ‘Advanced Car Kit’?