Derived from those Japanese endurance gameshows, I switch the seat heater on to full power and see if I can make it the 15 miles from home in Stamford to work in Peterborough without turning it down. As yet, I have reached Wittering (six miles), but am hopeful of reaching Alwalton (13) due to the purchase of some extremely sturdy trousers, because the Astra has the hottest seat heaters my bottom has ever tested.
In fact, the only time I have ever maintained the infamous 'notch five' was when the sun finally came out and I could get the roof down. As it was early spring and very cold, this negated the record.
What all this masochistic pleasure proves is that Vauxhall has thought long and hard about the needs of the British convertible driver, as along with Sizewell B tucked into the cushion, the Astra has a furnace-like heater as well.
And on really cold mornings, the hood has provided excellent insulation and the rear screen has demisted efficiently. When the sun finally came out, getting the electrically- powered roof down took a while with much whirring and clunking, but it burrows neatly down under the bodywork, and I love the tidy Bertone-styled lines.
Unfortunately I've got self conscious due to the colour. Although in tests I don't usually mention this because we often get what we're given and not what we'd like, the violent honeycomb-centre-of-a-Crunchie tone of the Astra screams 'hairdresser chic'.
Other drivers have complained about the comfort, or lack of it, of the front seats. They're leather, don't seem to have much give, and are flat and broad. I have found them fine, which may be because I am equally as broad so they fit me.
What is particularly noticeable is the scuttle shake, especially when cold. I've seen a few reports that say the Astra doesn't suffer much from having the roof chopped off, so perhaps ours is an exception, but over uneven surfaces it sometimes flexes like Rolf Harris' wobbleboard, and there is a constant high-pitched rubbing sound, like the excited chatter of gossiping mice.
But the 2.2-litre engine in the Astra is strong enough and provides plenty of ready power, particularly in the second half of the rev range, and the trip computer is claiming 30.6mpg after nearly 2,000 enthusiastic miles. The thing is, you have to remember that for £19,000, the Astra is a fully electric convertible which looks great, and goes very well.
There is no way it can have the refinement of premium soft tops for the price, but I would happily live with it, despite its faults - as long as it had a respray.