Once you've got a box on the bike, these are the parts that make it livable: canopies, covers, cushions, nets, and hooks that turn a bare crate into a weatherproof, kid-friendly, load-secured space. Rain canopies from Rad3, Convoy Products, and Hardus Velofurn snap over the box to keep passengers dry; waterproof covers and tarpaulins from Clarijs and Hardus seal cargo against the weather; cargo nets and cushions from Studio Vollebak hold loads down and pad the ride.
Prices run from around 30 EUR for a net to 580 EUR for a full canopy set, so you can add one piece at a time. The main thing to check is that the accessory is made for your specific box, since canopies and covers are cut to match a named model, not a universal size.
Buying the box itself? Start with hard boxes. Need full weather protection for the whole bike? See covers and weather.
