Sat navs and car accessories How we test roof boxes

How we find the best roof boxes

Roof box testing shot

Finding how well each box would fare in a crash

If you plan to holiday in Blighty then the chances are that rain is likely to make an appearance at some stage, so we checked the roof boxes were waterproof using a high-pressure cleaner from the front and side to replicate heavy rain while driving at speed.

To make sure the boxes were tough enough to endure the rigours of a family holiday, we put loaded each one up with typical holiday gear, put them on a sled and subjected them to an impact. 

Afterwards we inspected the boxes for damage and whether their contents had moved around excessively. We also made sure they stayed firmly attached to their mountings.

Temperature extremes

The boxes were tested for how well they withstood severe temperatures. We subjected them to temperatures of -20°C for 12 hours and gave them a minor drop test to see if they had become brittle. 

Then we cranked the temperature up to 60°C and checked for any deformation. Extreme? Yes, but at least you know that Which? Best Buys really are the best of the best.

Other sections in this guide

  1. Overview
  2. Best Buy roof boxes
  3. Other roof boxes on test
  4. Roof box features
  5. How we test roof boxes
  6. How to buy a roof box