Even though we saw the general outlines of Audi's upcoming 2012 A5 DTM race car at last fall's Frankfurt auto show, its final design, particularly in terms of aerodynamics, has been in constant flux since then, with on-track testing being done at increasing levels of secrecy. As of yesterday, the car is finalized, as testing has closed and the design has been homologated.

Just under 60 days remain until the start of the DTM season, at the Hockenheimring, where the new Audi will kick off its 2012 defense of the marque's 2011 title.

Special attention to detail has been taken this year, as Audi is expecting very close competition from Mercedes and newly-rejoined BMW. With more shared elements between the cars this year than in seasons past, and additional rules regarding each car's unique aerodynamics, the testing period has been intense.

The work has been successful, too, according to Audi factory driver and 2010 Race of Champions winner Felipe Albuquerque. "I expected quite a bit of it, but I wouldn’t have thought that the step would be so big," he said. "Particularly in fast turns the new A5 DTM handles like a formula car. Truly fascinating! I think I’d have to readjust quite a bit if I switched back to the old A4 DTM."

For more details on the A5 DTM, read our original coverage--and see our live photos--here.