The annual post-September fall in convertible values may become a thing of the past as metal folding tops take over from the traditional fabric roof.

Recent years have seen the UK leap to second place in the European convertible market, with only German drivers more fond of open-top motoring.

The British climate prompts a slump in demand for convertibles as autumn approaches, leading to a significant reduction in used values during the winter months.

But Jeff Knight, forecast manager for CAP Motor Research, said: “The convertible market is seeing a lot of new entrants that are significantly different from the traditional offering in one crucial respect.

“Take Ford Focus CC, Vauxhall Astra Twintop, Volkswagen Eos and the already established Peugeot 307 and Megane CC. The feature they all share is the metal folding top.”

However, Knight believes that only time will tell whether the additionally weather-proof comfort offered by a hard top that opens and closes at the touch of a button will increase the appeal of a convertible during the cold, rainy season.

He said: “The seasonality of convertible pricing in the used market relates directly to the weather, with a slump after September and a steady rise from spring onward.

“However, the metal folding top is a relatively new technology in the volume car market and that means waiting to see how it performs long term. If such mechanically complex equipment suffers long-term reliability issues then the presumed advantage of sealing the elements out more securely will be dissipated.”