'I was recently down in Majorca driving the new Mercedes-Benz CLK Cabriolet. A couple of late March days in the Med sounds idyllic – except for the fact that the first day was warm but cloudy while the second day, which was the main driving opportunity, brought torrential rain.

The Mercedes-Benz UK people and their German colleagues actually apologised for the weather, as if they could be blamed! On the other hand I saw it as a great opportunity to put a new convertible through its paces. And I can report that it performs superbly in the rain, with not even a drop of water appearing inside the cabin. Most drop-head launches are held in sunny conditions so you rarely have to put up the roof, so these conditions were a blessing for anyone who wanted to dig underneath the image.

Perhaps other manufacturers would benefit from a few storms during their convertible launches if they really wanted to make a point about quality. And quality is vital for long-term success in the used market, long after the glamour of the launch.

Here at home we had a fantastic March for weather, which brings me to my personal theory on how the weather may affect car sales. Some supporting evidence comes from the fact that most dealers have been reporting a fantastic March – some claiming their best ever.

Then again, low interest rates and good deals on new cars obviously have a massive impact, too. And, of course, many registrations were also brought forward from April to take advantage of bonuses. But who can blame the industry for making hay while the sun shines?'