Thule Mountaineer Car Top Carrier
"Full-size cargo box perfect for your family vacation on a mountain top or on the beach. 17 cu. ct. Capacity; 100 pound carrying capacity; 91.5 in. L, 28.2 in. W, 16.6 in. H. Fully assembled. Carries 6-8 sets of skis. Mounts to most removable and factory-installed roof racks with at least a 150 pound capacity"
A car top carrier is great to have if you're traveling with golf clubs, skis or a lot of luggage. Sears is one store that carries a nice selection of car top carriers by Thule and X Cargo. You can find a range of different carriers in various sizes and styles. Some of these carriers are quite large and can fit a large of baggage and equipment, whereas others are smaller.
X-Cargo X-Treme Car Top Carrier
"Aerodynamic 16 cu. ft. carrier holds up to 100 lbs. of evenly distributed cargo and is perfectly sized to allow rear hatch access to SUVs and cross-over vehicles. Holds luggage, camping gear, sports equipment and more. Fits most vans, SUVs and cross-over vehicles with factory-installed or aftermarket roof rack systems rated at 150 lbs. or more."
If you have a luggage rack, you're in great shape. Generally, factory racks are rated from 75 to 250 pounds. It's important you check and follow the limit. Most any car top carrier bag can be strapped into any rack as long as it has raised bars. If your luggage rack has crossbars running the width of the car, you can also use either a roof basket or a rooftop cargo box. Consider the following when choosing a roof cargo solution: