They are infuriating because they're so common in today's cars; because they'd be so easy to fix; and because even the small, skilful team of engineers that developed the Twingo - a relatively low-budget 'niche' vehicle - made the same silly mistakes as the big committees that developed Fords, Vauxhalls, Peugeots and mainstream Renaults.
Surely engineers who can perfect anti-lock brakes that modulate pedal pressure 10 times every second, invent airbags that inflate in 25 milliseconds, and come up with prototype petrol engines so clean that they filter city air rather than pollute it, can give us pockets and bins to hold envelopes and coins and credit cards, and rain gutters that stop water spilling on to the seats and carpets when the doors are opened.
The Twingo, to be fair, has a bin on top of the dash, and another shelf beneath it. But go around a corner, and your letter or coin or credit card soon slides off, ending up on the carpet and then usually under the seat. There are door map-pockets, but as with most cars, they are thin and shallow, and awkward to get to in a hurry. Glove boxes are also hard to reach, particularly with your seat-belt on. Centre console bins are probably the best bet for storing oddments. Trouble is, they are usually too shallow, too small, or completely given over to storing cassettes.
Probably the best manufacturer at offering good space for odds and ends is Vauxhall. For this, we can thank the fleet market (it is probably the only thing for which we can thank the fleet market: in general, the proliferation of company cars has massively lowered the standard of driving, and made the choice of cars duller and more uniform). Vauxhall sells a disproportionately high number of its cars to the fleets. Drivers who spend whole days inside a tin box like the convenience of being able to store their fags, crisps, coins and mobile phones nearby.
The loss of rainwater gutters - old cars used to have them - and the consequent dampness of seats and carpets is the fault of aerodynamics: or rather the maker's obsession with it. Those gutters offered air resistance. That meant there might be more wind noise at 80mph, and you might lose 0.5mpg on a motorway run from London to Manchester. Personally, I'd rather not get wet.
At least the Twingo avoids that other aspect of the fashion for a slippery shape: low rooflines. Modern cars offer considerably less headroom. In my 1953 Citroen Light 15, which I sold recently, the rear passengers sat upright, as in a big lounge-chair. Modern cars - apart from the Twingo and one or two others - have much lower roofs, which require more reclined and therefore less comfortable rear seats. Such a position is also less space-efficient. The human body needs less room, fore and aft, if sitting upright than in partial recline. My old Citroen had a shorter cabin than, say, a Ford Sierra, yet in real terms it offered more leg and knee room.
If I have one great grievance about car detailing, though, it is radios. They are, almost without exception, appallingly badly designed. For starters - and this is the fault of the car makers, not the radio firms - they are normally stuck at the bottom of the dash, not at the top. To use them you have to stretch awkwardly and take your eyes off the road.
There are a few exceptions, particularly Volkswagen, which usually puts its radios up handily high. Honourable mention must also go to Renault, whose remote-control radio stalks - little wings on the steering column - allow tuning without taking your hands off the wheel or your eyes off the road. Top-line Renaults have the feature; it is optional on cheaper models, and not offered on the Twingo.
More galling is the difficulty in using modern car radios. The specially designed Grundig in the Twingo has tiny buttons that are far too close together. The Philips unit in my wife's Renault Clio is similarly blighted, as were Becker and Blaupunkt units in recent pricey German cars I ran. On/off buttons are often almost impossible to find, partly because there are so many superfluous buttons. And at a time when normal transistor radios and cassette players are so cheap, it beats me why car radio/cassette players should still be so expensive.
I could go on listing the things that irritate me about modern cars. If you've got some favourite things you hate about cars, drop me a line at the Independent. I'll run a selection next month.