When planning a trip with bulky luggage, it is easy to compare roof boxes by litres. Start instead with a compatibility card covering your car, rack and the exact box model. It can rule out an unsuitable listing before you arrange a viewing.
Write down five figures
Record the vehicle’s roof limit while travelling, the complete rack and feet weight, the empty box weight, the rack rating and the box’s cargo limit. Beside each figure, note where you found it: a manual, label or manufacturer’s reply. Do not replace missing information with a similar-looking number from another listing.
A worked example
These are invented figures, not specifications for a real car: a 60 kg roof limit minus a 4 kg rack and feet minus a 16 kg empty box leaves 40 kg for luggage under the vehicle limit. Separate rack or box restrictions may reduce that allowance. Check what each rating includes. For travelling, use the dynamic limit rather than a parked or static limit.
Sort your intended luggage into groups and weigh each group with its bag. Put the total next to your calculation. Do not add a heavy item by guesswork simply because there is space left inside.
Ask the seller for useful evidence
- The exact model and a photograph of its identification label.
- Details of the included mounting kit, keys and internal straps.
- Any known cracks, repairs or altered mountings.
- The instructions for that particular version.
Check compatibility and installation against the vehicle, rack and box instructions. Before travelling, check attachment, secured luggage, lid closure and locking, and account for the vehicle’s total height. Resolve unknown limits or fit before loading. A photograph of an intact shell cannot establish compatibility.
A more useful listing
Include the model, supplied parts and photographs of labels and defects. Those details help a buyer more than a claim that the box “fits everything”.