With dozens of sets on the market, it is all too easy to get lost when trying to pick the best portable satellite navigation system. We put 20 to the test to help you find your way through the maze. Complicating the choice for drivers is the new breed of combination units, which offer guidance and also include safety camera location warnings.

To find our winner, we looked for clear instructions and an uncluttered display, plus full postcode programming, up-to-date mapping and a large database of points of interest (POI).