One of the benefits of car camping is that you don't need to worry about the weight and versatility of your sleeping gear and can focus instead on comfort

Steps
1. Thumb through a couple of reputable outdoor magazines for equipment reviews and articles about equipment purchases to find out the most recommended models and manufacturers of sleeping bags.

2. Figure out what you are willing to spend. Good sleeping bags range anywhere from $80 to more than $300.

3. Consider the season and temperature you're likely to be camping in and look for bags with the appropriate temperature rating. Winter bags are the warmest you'll find and are rated to as low as -50 degrees; three-season bags start at at around 15 degrees and range upwards.

4. Consider the likelihood of your bag getting damp or wet. Down bags are cozy and toasty warm, but are also expensive and disastrous when wet; synthetic-filled bags are less expensive and will still insulate even if they get wet.

5. Consider whether you are likely to be sleeping alone or with a partner, as this will help you choose the shape and length of your bag. Rectangular bags are roomier at the feet and are more spacious when zipped with a bag that has a mated zipper; mummy bags are warmest for solo sleeping because they fit tightly and insulate the shoulders, neck and head.

6. Consider how long you hope your bag will last. Down bags are the most durable and don't need to be cleaned very frequently; the fibers in synthetic-filled bags tend to break down after a while and lose their "loft."

7. Look for a bag with a zipper that opens from either the top or the bottom of the bag. This is especially nice for camping in warmer weather - just open the bottom zipper to cool off or ventilate your perspiring feet.

8. Try the bag out for size before you purchase it. Make sure it's just loose enough for you to sleep with layers and turn over inside of it, but not so loose that it won't insulate you properly.

9. Don't cut corners once you have decided what you need - the comfort of your bag can make or break your camping experience. Buy a reputable brand from a reputable outdoor company, and make sure you have a lifetime warranty.