Though I pride myself in taking eco-friendly breaks – I haven’t flown on holiday for around 15 years – I have to confess that I haven’t quite got over the love affair with the car, and would be very sad to have to replace my Saab with something like this.

One of the fun features of the Saab is a button labelled Night Panel. The idea is it switches off as many unnecessary lights and dials as possible, to avoid distraction in the dark. (It’s even fun in the daytime as all the analogue dials except the speedometer drop back to nothing, as well as losing their illumination.)

I rarely use this, as I am male and therefore like driving a car with an instrument panel that looks like something out of a jet fighter with lots of twinkly lights, but last night I was driving down a country road to Salisbury for a book event at the Cafe Scientifique there, and thought I’d give it a go.

It was the first time I’d used it on this particular Saab, and I was slightly surprised to see that one of the things it did was switch off the illumination for any speed over 90 miles-per-hour. The rest of the speedometer disappeared.

It was only a slight surprise, because I had already discovered one of the Saab’s other interesting habits. When having the chance to drive at silly speeds on an autobahn, I discovered that over 85 miles per hour you get a ‘ding dong’ and a panel lights up warning you that you are doing over 85 miles per hour. What? Bear in mind that this is a car with a speedometer that goes up to 160. Now admittedly speedos always go a long way over the maximum, but this was ridiculous. And why 85?

Meanwhile, back at the night panel, I did wonder what would happen if I had driven at over 90. Would the rest of the speedometer light up, or would the car would gently tell me it’s too dark to go so fast? Or maybe it would just leave my speed a mystery. But not being on an autobahn, I couldn’t find out.

It also made me wonder if we could have other technology that limited the user in certain conditions. Cars that wouldn’t start if there was too much alcohol on your breath. (Actually, I think these exist.) Beer mugs where the bottom falls out after the nth pint. TVs that switched off after 3 minutes of Big Brother. Hmm…