The first consideration when choosing a car roof box is the amount of space you need. The size of your family and vehicle will provide some initial parameters to make an initial assessment.
A box for an average vehicle will have a storage capacity ranging from 300 to 450 liters, which generally will store sports equipment for two to four people. Larger capacity boxes with over 500 liters of storage are available for larger vehicles.
A shorter box will be ample space for the necessities of an end or to carry golf equipment, while skiers will need one of the longer variations. If you are an avid cyclist and need to bring a mountain bike or two on the roof, you may still be able to use a long, slim box that only takes up a portion of the roof space.
Car roof box materials
Best car roof boxes you can buy are rigid and made of sturdy plastic or fiberglass, and many have metal reinforcements. You can choose a gloss or matte finish. The only consideration other than personal preference is that glossy finishes are usually a little easier to clean.
You won’t have to do much to keep the finish of a car roof box clean because most are treated to be scratch-resistant and protected from the sun’s rays. A nice advantage
Rooftop cargo boxes (more info at https://www.withcar.it) require your car to have a roof rack system with crossbars. Car roof boxes or attachment accessories are often universal, built to fit any track.