Every morning it was a joy to thumb the starter button and hear its heavy pulse, the valved exhaust staying open for five or six seconds for extra resonance

Right from the start, the RS4’s depth of quality impressed. Every control is infused with a slick, solid tactility, the gearshift tight and precise, the steering fluid and direct. Sure, the drivetrain would illuminate any lack of gear-changing finesse but I quickly got used to it. In those early months there were forays to Europe’s greatest circuits: Le Mans, Spa and the Nürburgring. The RS4 provided swift, cosseting transport to all three, but the high spot of my time with it came at the ’Ring. We were there to compare and contrast an original Ruf CTR ‘Yellowbird’ with the latest Rt12. The day started wet and, wary of venturing out in the generously owner-loaned, 700bhp Rt12, I took the RS4 out to reacquaint myself with the track.

By mistake (ahem) I’d purchased a ticket that gave enough laps for the photoshoot and quite a few more. They were all gone by the end of the day, and my respect for the Audi was even greater. One reason the RS4 is so well balanced is that its four-wheel-drive system’s front/rear torque split has been tweaked from the traditional Audi 50/50 to 40/60 in the favour of the rear. While the V8 gave it the grunt to make every mile of the track exciting, it was its accuracy, neutrality and, most of all, its unflappable poise over the trickiest, bumpiest sections that I admired most. The fact that it averaged 24mpg for the round trip was quite impressive, too.

A couple of months later, Mr Lee, our art editor, loaded up the RS4 for a trip to Le Mans to see the Audis win again. Being the fastidious type, he checked the oil. I’d put a litre in the month before but Chee found that it needed another. Hmmm. Setting aside the concern of an apparently growing thirst for a moment, if you want to take advantage of the extended service schedule, which puts the first service at 18,000 rather than 12,000 miles, you must top up with ‘long life’ oil, not just regular synthetic stuff. It’s hard to find, and expensive when you do – Chee paid £17 for a litre.

He’d put another half litre in on his return and over the next couple of thousand miles I kept a very close eye on the level. It didn’t budge but I decided that with a near-100bhp-per-litre, 8000rpm-plus V8 at stake, I’d book the RS4 in for its first service at 12,000 miles. As it turned out, this didn’t happen until around 14,000 miles, delayed because the necessary parts were on ‘back order’. My local dealer, Peterborough Audi, spoke to Audi UK and they agreed that I wouldn’t be liable if the engine went pop before the service.

Two additional items were on the job list: the parking sensor squawked every time reverse was selected (traced to the front numberplate coming unstuck at either end and getting in range of the sensors), and the engine was a little lumpy from cold and would very occasionally lapse into a slight misfire after a foray to the limiter. On cue, the misfire appeared for the technician in the passenger seat. The solution was a new engine ECU map, and this would take a couple of days to come from Germany. The bill came to a reasonable £319, the additional work carried out under warranty. Well-worn front brake pads were flagged up, and as the misfire was so rare I told the dealership I’d wait until the pad warning light came on and get the two jobs done together.

Just before the service all four tyres were replaced, the original Pirelli PZeros succeeded by another of the OE (Original Equipment) fittings, Michelin Pilot Sport 2s. It’s always hard to judge any changes when you’re going from a worn set to a brand new set, but after they’d bedded in I reckoned the steering felt lighter and the grip a fraction less strong. Not that that matters a great deal in the RS4; no matter what the weather, it remains hooked-up and confidence-inspiring. Overall, though, I preferred the feel of the Pirellis.

I realised just how far the RS4 had got under my skin when I flew back into Stansted after the second week of Car of the Year in the South of France. It had been a blinder, with the 599 GTB, Murciélago LP640 and 911 GT3 squabbling over the top slot. Yet it felt so good to slot back into the RS4 and thumb the starter button. On the drive home it struck me that it shared many qualities with the Porsche; the same sense of integrity, of tautness and precision and durability. Similar stupendous power delivery, too. Of course, they diverge when it comes to on-limit dynamics but I’ll bet the up-coming four-door Porsche Panamera isn’t edgy and challenging like a 911. In fact, I wouldn’t be at all surprised if it was four-wheel-drive.

At the end of a long-term loan it’s always satisfying to hand a car back in the same fine fettle in which it was delivered. With the 12-month loan deadline looming, that’s how the RS4 was. Well, with the exception of the front discs, which under pressure revealed slight warping, largely as a result of chasing the Monaro VXR500 along the autobahnen (evo 103), during which it hit its speed limiter and an indicated 165mph a couple of times.

Then, with just a few weeks to go, a driver-less truck rolled into the front at about 1mph, scarring the bonnet and grille. Then the windscreen was cracked by a stone on the way to Cadwell Park for RaTCoty, and hours later the footrest fell off while David Yu was driving. I was disappointed at the footrest; it seemed so out of character. The occasional misfire had never occurred again, the engine’s oil consumption had settled to an acceptable litre every 4500 miles or so, and the lumpy cold running was about to be cured, too.

An RS4-owning reader had tipped me off that an ECU upgrade was installed as a matter of course whenever an early car was presented for service, so I called Peterborough Audi and they confirmed the upgrade was available, free of charge. I booked the RS4 in. And the brake pads? Perhaps they’d been over-cautious, reckoning they wouldn’t make the next service (it had been to the ’Ring, remember). Whatever, 10,000 miles and eight months later, still no sight of the pad warning light.

The ECU upgrade was a while-u-wait affair taking about an hour. As I drove away, I recognised that the V8 had a much brighter, more willing mid-range, and the next morning it was a model of smoothness, the only disappointment being a reduced idling time with the valve open. A few days later the RS4 was gone. Tormentingly, it returned briefly, refreshed, for a meeting with the new V8-engined M3 (108), but I wasn’t on that test.

Very marginally, the M3 won again. Still, I reckon the RS4 has improved Audi’s standing among enthusiasts in a more tangible way than its multiple Le Mans wins; it stands as showroom proof that the team at Ingolstadt has a strong grasp of how to make an exceptional road car. I’d argue that it’s also laid the ground for the acceptance of the mid-engined R8.

Would I change anything? Only the flat-bottomed steering wheel with its metal-trimmed lower edge. It looks good but should you ever find yourself grappling with handfuls of lock, it would be better to have a fully round, leather-trimmed rim. But then, what am I thinking: this is no BMW M3…