Show me someone who’s utterly contented with their children’s school work, their houses, their cars and the places they choose to go on holiday. And I’ll show you someone who’s a damn sight happier than me.

Once, I thought I’d found the “perfect car”. I was driving through an agonisingly pretty bit of Italy, on the most glorious summer evening, in a Ferrari 355 and I remember turning to the camera and saying: “I think I’m experiencing motoring perfection here.”

So I came home, bought one and quickly found that actually it had the driving position of a Seddon Atkinson dustbin lorry, a sticky throttle linkage, and that if you wanted to service the engine it had to be taken out of the car. This cost eleventy billion pounds.

Perfect? It was nothing more than a rung in the ladder of constant improvement that has brought us today to the Ferrari 430. And that isn’t perfect either. It looks like a trout that’s just won a cider drinking contest.

I’m never quite content with anything. I went on holiday earlier this year to a smashing hotel in the Caribbean that had just about all the bases covered. Except it was full of rather too many people who spend rather too much time donating to the Labour party.

Then there’s the view from the back of my house. It’s wonderful. Faultless in every way except that away off on the far distant horizon there’s a telegraph pole. And that’s all I see when I look out of the window. Everyone else sees the glorious Cotswold countryside. I see the pole.

My eye seeks out the imperfections in life and glosses over the good. The first time I walked down New York’s Fifth Avenue I was disappointed that the buildings weren’t taller. When I first met my wife I thought her lipstick was a bit too red. Nothing in my life is ever quite right.

I’m currently reading a book called The Power of the Dog for the second time in a week. Why? Because on the first pass it appeared to be utterly blemish free, faultless. And to my mind that can’t be. So I’m reading it again to find the little mistakes, the passage that’s a bit too long. The squeak of dialogue that doesn’t ring true.

I did that when I went to see what is still my favourite film: Local Hero. First time round, I thought it was wonderful. Second time I thought Jenny Seagrove’s webbed toes were a bit silly.

Then you have the greatest quotation in human history, uttered when Neil Armstrong stepped onto the moon. But it’s not quite right, is it. Because if it was one small step for a man, then it must have been one small step for a mankind. And that doesn’t make sense.

All of this, as I’m sure you’ve guessed, is leading me to the Audi A4, a perfectly reasonable saloon car, spoilt for me — naturally — by a styling crease that runs down the flanks. You don’t notice this, however, on the RS4 because it has massively flared wheelarches shrouding huge low-profile tyres. You know, just from looking at it, that it’s going to be very, very fast. And it is.

It was designed to be a rival for the old BMW M3, but if anything they overshot. The BMW had a 3.2 litre six cylinder engine. The Audi was given a 4.2 litre V8. The BMW came at you with 343bhp. The Audi churns out a remarkable 420.

Of course a new BMW M3 is waiting in the wings and that will have a V8 too, but for now Audi’s running the only game in town and it’s a game, I guarantee, you’ll want to play. I drove an RS4 last year in the south of France — which is a stunning part of the world spoilt by too many Russians — and I loved it.

It was the first Audi for 15 years with steering that feels connected and suspension that doesn’t shake your hair out. And then there’s the engine. Oh God, the engine. It’s a masterpiece, as peerless as the Koh-i-Noor.

I hurled that car up mountain passes at speeds that boggled the mind and I enjoyed every minute. Except for the minutes when I was stuck behind Dutchmen in caravans. But there weren’t too many of those because with 414bhp on tap, and four-wheel drive to put it on the road, you can overtake in gaps smaller than a stripper’s knickers.

That said, it wasn’t perfect. The optional bucket seats were so massive that there was no legroom in the back at all. None. So you were being asked to spend £50,000 on a four-door four-seater sports saloon that couldn’t take four people.

You have the same problem in the even more expensive RS4 convertible I was using last week. Even though it had normal front seats the space in the back was so pitiful there wasn’t even room for my children, and the boot’s pathetic too.

However, while this may be an issue in the saloon, where practicality is the raison d’être, it doesn’t matter at all in the soft top because, as I’ve said many times, the only person who ever looked good in the back of a convertible was Hitler. Everyone else just looks embarrassed. Or, in the RS4, squashed. And a bit frightened.

As with the saloon, the whole experience is dominated by the engine. It sits in the mix like Nelson Mandela would sit in a room full of accountants. And I love it. I love the noises it makes — you want to have the roof down just to hear it more clearly — I love the even spread of torque, but most of all I love the power.

Jaguar uses a supercharger to eke 400bhp from its 4.2 litre V8. But with no extra assistance at all Audi gets 414bhp. And it’s delivered through all four wheels so there’s no unpleasantness; you push the throttle and you go past 60mph in 4.9sec and on to a limited top speed of 155.

And that’s just the start, because on the steering wheel there’s a little button marked S for sport. A lot of car makers fit various models with sport buttons these days, and all claim they sharpen up the suspension and change the steering. Really? Most of the time they seem to do nothing more than ignite a “sport” warning light on the dash.

Not in the RS4 though. Its S button changes the throttle control mapping and renders the car almost completely undriveable on the road. It’s a button you should only press when you’re on the track or when no one is looking. Pushing it is like the moment when Kevin Bacon pushed that button to stir the oxygen tanks on Apollo 13. Suddenly you’re flirting with gimbal lock . . . whatever that is.

I left it well alone and sat back to revel in a car that goes like double cream, sounds like God snoring, and is every bit as poised and controllable as the old BMW M3. That is extremely high praise.

The nose heaviness of previous fast quattro cars has been eradicated by fitting aluminium front wings and mounting what’s already a small engine backwards. Oh, and the four-wheel-drive system sends 60% of the power to the rear wheels, which is really where you want it. I liked the way this car looks, I liked its quality, I liked the way it was civilised, roof up or down, and I liked the intuitive way all the controls work. Even the sat nav.

Of course, it isn’t perfect. It can’t be. Nothing in my world is. But I’m genuinely struggling to think what might be wrong with it. I’m therefore going to do what I did with Local Hero and The Power of the Dog. I’m going to keep on testing it until something crops up.

So, I’m going outside now. I may be some time.

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