The RS4's figures are mightily impressive – 415bhp from a 4.2-litre V8, 0-62mph in 4.8sec and a theoretical top speed of more than 180mph, but restricted to 155mph. More impressive still is the car's flexibility and ease of use in everyday conditions, so you're not forever fumbling with the six-speed gearbox.

With lowered aluminium suspension, 18- or 19-inch alloy wheels and serious Pirelli tyres, the RS4 has prodigious grip. A reworked four-wheel-drive system normally sends 60% of the power to the rear (but this can vary as necessary) and provides fantastic traction. The surprise is how well resolved the ride and steering are compared to past performance Audis.

For normal running, the RS4 is a highly civilised road car, despite its large wheels and tyres. Even the V8 engine noise makes itself scarce when cruising, although there's a delicious growl when you provoke it. You can intensify the note and sharpen throttle response just by pushing a button on the steering wheel.

The RS4 isn't cheap at just under £50,000 (£8000 more than the BMW M3), but nor is it excessive considering the technology it contains. Given the limited build numbers, don't expect discounts. However, this should work in your favour come resale time. The 20.9mpg combined fuel figure is pretty impressive for a car with such performance potential and the considerable weight of four-wheel drive.

Trim quality is up to the usual Audi standards and the reliability of major mechanical components should leave little to be desired, but niggles with the suspension are not uncommon. The good news is that the A4 on which the RS4 is based seems to be largely immune from the criticism.

Audi claims that the RS4's structure is so strong that there's no need to fit side airbags, although two-stage front airbags and curtain 'bags are fitted, and there's a long list of active safety features. The A4 traditionally performs well in tests of its anti-theft measures, too.

Sculpted Recaro sports seats, metal pedals and a flat-bottomed aluminium-look steering wheel leave you in no doubt what you've bought, but the fine ergonomics and driving position of the regular A4 remain undamaged. In the RS4, you start the engine with a console-mounted button but still need to put the key in the ignition first.

The quattro four-wheel-drive system enforces a hefty transmission tunnel, which denies the RS4 adequate foot space for three in the back – just as in any other A4. That restriction apart, this is a roomy and comfortable four-seater with a well shaped and sizeable boot.

You get all the things found in other high-spec A4s plus a Bose sound system with 10 speakers, the option of Nappa leather upholstery or race cloth and leather, the central starter button and the more sporty wheel, pedals and seats.