Is there such a thing as a 'perfect' car... and if there is, would you actually ever want to own it?
Yesterday, I went for a small drive in the Audi RS4 estate and thought, after a small while, that it may be the most complete car money can buy. It's fast, practical and not at all ostentatious.
But then I came home, gave the matter a bit of thought, and realised that actually, it's no more complete than an unfinished jigsaw. The front seats are so huge, there's almost no leg room in the back at all, and it is extremely expensive.
So then, this being a wet bank holiday Monday, I started to wonder if there really is such a thing as a complete car. We talk, often, about the world's fastest car, and the world's greenest car, and the world's most economical car. We bask in the magnificence of the Rolls-Royce's ride and we marvel at the extraordinary reliability of the Honda V-tech system - 15 million made and not a single warranty claim so far.
But is there a car that brings all of these things together, wraps them up in an easy-to-digest, value-for-money package and is sitting there on the shelves right now, waiting to be identified? Because if there is, you can forget the Phantom and the Veyron. It would have to be the greatest car in the world.
I'm talking about the automotive equivalent of someone who never existed: think of a person with the naval skills of Admiral Nelson, the writing prowess of Sebastian Faulks, the engineering pizzazz of Isambard Kingdom Brunel, the political brilliance of Nelson Mandela and the looks of Jim Morrison.
Of course, you may think it's impossible to combine, say, comfort and handling. You may argue the two things are mutually exclusive, and you may continue to argue this until you step into the new Audi R8 which will prove you wrong. Even without its magnetic suspension, it manages to handle and is so smooth you can run over a medium-sized man and not notice.
It's the same story with fuel economy and speed. You may say any car capable of blistering the skin off your face with its pace and panache will, by its very nature, gorge on fuel in the manner of a hot dog presented with a refreshing mountain beck. I don't even need to stray beyond Audi, again, to show you you're wrong. The A8 with the V8 diesel goes like a ******* but can, if you're careful, return in excess of 40mpg.
Sadly, however, the A8's claim to be a complete car stops at this point because the ride gives you some idea what it might be like to be washed through a crazy-golf course by a large flood.
And like its little sister, the RS4, the A8 is not cheap. Which brings us neatly onto a serious contender for the elusive complete-car title: Vauxhall's new VXR8.
I've argued in the past that a McMeal represents better value for money than anything else on earth. You get all you need for a balanced lunch - salad, bread and meat - and then they throw in a roof over your head, some utensils, a zesty drink and a free toy.
The only thing that comes close is a national newspaper. They amass stories from around the world, write them, take pictures, send it all off to a printer's and have the whole lot delivered to your doorstep, even if you live at the top of Scotland, the next day!
Obviously, the VXR8 costs more than 50p, but if you look at it in the context of its rivals, then it's a revelation. Because this 6.0-litre V8 saloon car produces 414 bhp - exactly the same as you get from an RS4. Yet, in round figures, it costs £15,000 less.
You look for any outward signs of where the savings might have been made and they're there all right. But you try putting your finger on them. You need to think of this car as an own-brand hi-fi. It's not as good as a Sony. You know that. But you don't know why.
What you do know is that here, for little money, is a fast, exciting saloon car that can take five people and their luggage. Except of course, it's as green as Michael Winner's face, it has fuel injectors like a line-up of firemen's hoses and when you park it, you find yourself hurrying off in case anyone thinks it's yours. Boris Johnson would call it vulgar. My children say its chavvy.
In some ways, the Golf GTI still has more of a claim to the title than most. And yet, when you stop and think, it's not complete at all. It isn't a convertible, for instance. And you can't take it across a muddy field. Not if you want to get to the other side.
What I'm looking for here is the automotive equivalent of my favourite European city, Biarritz. It's in France, which means it's beautiful but like you, most of the people there hate the French, because they're Basque. It's on the seaside which means you get a beach, which is relaxing, but the sea's full of waves which makes it exciting.
The food is... well, let me put it this way: Biarritz is a spit from Gascony, and that's the epicentre. And it doesn't cost a fortune to get there.
Yet, I look through the lists at the back of this magazine and I can find something wrong with every single model in there. And when you think we've had the car for nearly 120 years, I find that a bit depressing.
But then I arrived at 'S', and sitting there was the Subaru Legacy Outback. I stopped for a moment and thought: "Hmmm..."
What is a Subaru? To those in bobble hats, it is a machine that comes out of the night and spits stones into your face. To those with baseball caps, it is a fire-breathing incarnation from the pixellated world of the PlayStation, a device whose pops and bangs enliven the local supermarket car park on a Saturday night.
But then to those in hats made from tweed, it is a car for the farm, something you used to buy, until recently, from the same place you bought your seeds and plough.
To those of an Impreza disposition, its four-wheel-drive system means better donuts. To those on the farm, it means you can reach a stranded sheep when it's two in the morning and snowing.
In town, we find the same thing. The eco-hobbits don't realise it's a four-wheel-drive SUV. It's just a rather fine-looking estate car which costs less than half what you're expected to pay for a similarly commodious Porsche Cayenne.
And to everyone, a Subaru stands as a shining beacon of hope that one day, all cars will be made this way. When you slam the door, it makes exactly the same sound as a recently shot pheasant hitting the ground, and that, as everyone knows, is one of the most satisfying noises in the world.
Plainly, this attention to detail goes further than the door though, because in every survey on reliability, Subaru always comes in the top five. But it's not a convertible, I hear you cry. That's true, but the last version I drove had such a massive sunshine roof, it may as well have been.
The Legacy Outback, then, covers more of the bases for more of the time than anything else. And that's the hardest trick of all. It's a big, small, fast, economical, well-made, cheap, fine-handling, comfortable SUV that's not an SUV.
Is it therefore the best car in the world?
Well yes, obviously, except for one thing: if I had £30,000 to spend on a set of wheels, I'd have an Alfa Brera.