For long road trips, a car carrier or cargo box is the best thing to use. It will relieve your baggage compartment and at the same time, it will also make your passengers more comfortable. It would be tough when the car is quite crowded and you are about to go for a long trip.
If you are planning to get a cargo carrier, there are a number of options you can choose from. They come in different types and you can learn about them here http://www.cargocarrierbox.com/best-rooftop-cargo-box/ and below:
Carrier bags – this is actually just like a huge bag that you can strap to your car roof rack. You can load anything here as long as they fit. This is also safe since it can be locked. You can just fold this as well if you won’t use it for the time being. The only thing about this is that this is prone to wear and tear when exposed to different types of weather and sharp objects.
Roof boxes – this is just perfect if you are fond of skiing as this product comes in two types, the long one, and the shorter one. The longer type can accommodate skis and other things. Both types are secure as they come with secured locks. When buying one though, you have to consider the type of vehicle you have.
Cargo baskets – this should be your choice if you are usually carrying bulky loads. These products are just open like a big tray actually where you can just load your things and strap them so they will not be thrown away.
All in all, most of these products are advantageous to own. However, you should consider the things you will usually bring with you before buying one.