All Natural Mommies - Diaper Bag
http://www.all-natural-mommies.com/cloth-diaper-bag.html

Pros:
This travel diaper bag is wonderful. If has a strap that fits over the back of your vehicle's seat. There are two sections - a top section for clean items and a bottom section (with waterproof lining) for dirty items. There are also two outside pockets to hold items such as bottles, toys, diapers, etc. This bag is very well made. The material is beautiful. The price is reasonable for this product. Bonus: this bag can also double as a changing pad if needed.

Cons:
The only problem I can see is the location you put the bag in your car. You may not want to put it behind a seat where your child sits because they would get their shoes all over it.