After months of secret research in laboratory conditions, Parkers can reveal that technology has gone backwards over the past 15 years.
Our case study revolves around the roof on Mazda's MX-5 - the popular lightweight roadster that's been in production since 1989.
We put two examples, with very differing roof technology, together for a straightforward comparison test. We expected a strong showing from a green 1.8-litre car from 1996 with a manual roof when pitched against a brand new red 2.0-litre model with one of those new-fangled folding hardtops.
Filming them side by side to expose the truth we were able to unpick this mystery. During filming we also measured the exact length of time it takes to get both roofs down and then back up again using a state-of-the-art measurement device.
A wristwatch.
To show the difference in speed between 1996 and 2011, our professional testers beeped the horn on their car when the roof was down and it was ready to drive away.
Find out which car came out on top in our spectacular roof-up/roof-down twin test.