Thule Interstate

Here's the thing — at 5.5 lbs and 16 cu ft, the Interstate is a waterproof rooftop bag that folds flat for storage. It works with or without crossbars, which makes it ideal for vehicles without a rack system. IP-tested seams mean actual weatherproofing, not just water-resistant marketing. The downside? No hard shell means zero security, and soft bags create more wind noise than rigid boxes at highway speeds.