So could the retractable hard-top have been nothing more than a bad dream that Europe's automakers are about to wake up from?

That's certainly the view at Audi to judge from table-talk at the recent A4 launch, the company convinced that its decision to stick with a conventional fabric roof for the forthcoming A3 cabriolet will be vindicated by the future direction taken by rivals.

I've got an interest to declare here: I've long regarded the retractable hard-top as being almost entirely pointless. Indeed, the first time I saw the horrendous proportions and molten styling of the Peugeot 307 CC I was very nearly sick. I still can't drive behind one on the motorway for more than a couple of minutes before having to either pass it or slow down.

Audi regards the RHT as being one of those contagious bad ideas that occasionally sweeps throughout the motor industry. Powered hard-tops add weight, complexity and cost to new cars, are a nightmare to package into the design and don't actually do anything better than a conventional fabric roof.

A soft-top typically weighs about 150 kg more than a conventional hatchback, a retractable hard-top tips the scales with anything up to an extra third of a ton on board. In coming years, where manufacturers will be fighting to shave every kilo from a car's kerbweight to reduce its CO2 emissions, that sort of weight penalty is going to be unacceptable.

We'll know how this one goes when we see which way BMW jumps. We know there was a fair bit of internal dissent within Munich over the decision to bring out a CC version of the 3-Series cabriolet, and rumours from within Germany suggest that it's going to be the company's one and only RHT. I'm hoping so.