With the arrival of spring typically marking the start of the convertible buying season, prices of popular ‘drop-top’ models could increase by as much as 20% in value over the next six months, according to used car retailer Carsite.co.uk.

After an extended winter, the return of warmer weather will be persuading many UK car buyers to look to a convertible or coupe cabriolet for their next purchase, with the increased seasonal demand pushing up prices in the sector.

Between 2009 and 2010, Carsite found the trade price of a Mazda MX5 1.8i increased from £10,450 in April 2009 to £12,350 in September 2009 – a rise of £1,900 or 18% – before falling £1,355 to £10,995 by April 2010.

A similar trend was also seen on a Volvo C70 2.4i Coupe Cabriolet which appreciated £1,600 in value from April (£14,395) to September 2009 (£15,995) before decreasing £1600 to April 2010 (£14,395). A Renault Megane 1.6 Coupe Cabriolet’s value also fluctuated more £1600 over the same period.

Seemingly less affected by the seasonal demand, a 2006 Porsche Boxster 2.7 increased only £500 from April to September, before falling just £345 to April.

Alistair Jeff of Carsite said, ‘In the peak months for convertible buying, prices can rise steadily all the way into September, adding between £1500 and £2,000 to the value of some models. Combine this with the appreciating nature of the used market at the moment, and we could be seeing greater seasonal variation than in previous years. Drivers looking to get an ‘al-fresco’ motoring experience this summer should be shopping around now.’