The revised range will feature four reworked petrol and two diesel engines and four trim levels, standard, SE, Sport and Sportline. Technical options include park assist at £750, and chassis performance equipment such as magnetic ride shock absorber control.
Jo Elliott, Audi UK's A3 product manager, said: "We have already seen magnetic ride on the R8 and TT but it is great to have this available on the A3, along with park assist, without having to wait for these to filter down to the range from more expensive models.
"At the moment we do not know what the take up of park assist or magnetic ride will be. We are in the process of dealer training and then it's down to them to get people into cars to try the systems out."
Elliott said Audi UK expects to sell 28,000 A3s in a full year, 9,000 three-door and 19,000 five-door Sportback models.
The range starts at £14,995 for the standard 1.6 rising to £27,720 for the 265bhp 2-litre S3 Sportback - available as a five-door for the first time.
Core competition for the A3 is the BMW 1 series although Audi is looking to pick-off customers from such cars as the Ford Focus, VW Golf and Vauxhall Astra as well as those downscaling from BMW 3 series and Mercedes C-Class.
Audi UK sales were up almost 18% in 2007 to 100,864 cars and in 2008 the company is so far running 5.4% ahead of last year.