There’s fierce competition in the prestige showrooms with Audi, BMW and Mercedes-Benz writes Chris Nixon.

There is no fiercer competition in the car showrooms of Australia than that between the prestige makes Audi, BMW and Mercedes-Benz.

This is where profit margins are high, especially with the fat options lists, and where the customer’s first step into a privileged world can lead to lifetime loyalty to the threepointed star, linked rings or spinning propeller. Although we think of these as expensive luxury cars, most buyers go to the more affordable “compact executive” ranges represented by the BMW 3 Series, Audi A4 and Mercedes-Benz C-Class (and, increasingly, by even less expensive ranges aimed at younger buyers).

The choice here is huge, as typified by a recently revamped Audi A4 and A5 lineup that now presents a total of 28 basic variants before option packs, individual accessories or other enhancements are added. Periodic model upgrades are routine as makers strive to keep their cars competitive,but for A4 and A5 this might be their final fling before scheduled all-new models are launched early in 2015 – and a good reason to buy now. The fourth-generation A4 sedan has been around since 2008; its good-looking sporty siblings the A5 Sportback, coupe and cabriolet came slightly later.

You’ll pay more for the A5 variants, but by-and-large you’ll get the same engines and transmissions as in the A4.The latest changes bring upgraded engines,more standard equipment and revised option packages across the range, but the focus is on the quattro all wheel drive models. More oomph is available with the 2.0 TFSI petrol quattro models, now with a heavily revised engine producing 165 kiloWatts (up 10 kW) and 350 Newtonmetres.

But perhaps more importantly, it’s now possible to buy an A4 sedan or wagon, or A5 quattro Coupe or Sportback with a 2.0 litre, four-cylinder diesel engine. This desirable combination of small 380 Nm diesel and all-wheel-drive should be a no-brainer for buyers, who until now have faced up to $20,000 more for the only diesel-quattro choice, a 3.0 V6. The sedan is priced at $65,800 before onroads and the Coupe and Sportback, $75,700.The A4/A5 ranges warrant attention from buyers wanting a compact prestige car. Audi has a reputation for excellent build,quality and comfort, but most importantly,neither of its German rivals matches its key feature, the security of all-wheel-drive.