Audi tweaks looking sound.

AUDI reckons the latest round of improvements to its A4 compact executive range make sound sense.

The SE and S-line versions are being fitted with a premium BOSE audio system as part of their standard specification.

The performance-oriented A4 S-line range expands to include a Special Edition model powered by a new two-litre turbodiesel engine developing 170bhp, while the entire A4 line-up gets cheaper option packages.

The sound system incorporates high-performance speakers with acoustics tuned to the specific architecture of the A4 saloon and Avant.

Normally an upgrade costing pounds 480 for Audi Concert II and Symphony II CD audio systems, it becomes an integral part of the SE and S-line specification at no extra cost.

Buyers of standard A4 models can upgrade to the SE free until the end of the year and in the process gain the Concert II radio with single CD player, 17-inch 16-spoke alloy wheels, cruise control and a driver's information system.

There is also a special deal on the S-line upgrade at a reduced cost of pounds 750, which adds 18-inch five-arm alloy wheels, sports suspension, special S-line body styling, part-leather sports seats, a three-spoke multi-function sports steering wheel and driver's information system.

The petrol-powered S-line Special Edition, which combines a more powerful 220bhp version of the turbocharged two-litre FSI engine with an enhanced specification is joined by a turbodiesel equivalent.

It is available in saloon or Avant form and in either front-wheel-drive or quattro four-wheel-drive configurations, costing from pounds 25,600.

There are also new option packages for the A4 range comprising communications, luxury, visibility and executive packs with savings of up to pounds 425 compared with buying the options individually.