Frankfurt — After more than $30 billion in fines, numerous indicted executives and a guilty plea in the United States, you wouldn’t think there was much more to learn about the Volkswagen emissions scandal.

Wrong. Nearly four years after Volkswagen confessed to systematically evading pollution rules for a decade, facets of the scandal are still coming to light. Newly uncovered documents viewed by The New York Times show that Volkswagen’s Audi luxury-car unit was more deeply involved in developing the emissions cheating scheme than previously known, and continued to sell vehicles with illegal software even after the scandal became public.

The documents, first reported earlier this month by German broadcaster Bayerische Rundfunk and the Handelsblatt newspaper, show that Audi managers and engineers in the Bavarian city of Ingolstadt were just as willing as their counterparts at Volkswagen in Wolfsburg to cheat in pursuit of the company’s goal of becoming the largest carmaker in the world — perhaps even more so.

“We won’t make it without a few dirty tricks,” an employee in Audi’s diesel motor development department wrote in an email to colleagues in January 2008, summarizing road tests that confirmed diesel models couldn’t meet emissions standards. Audi managers and engineers bluntly discussed what was in effect a criminal conspiracy, using terms like “defeat device” or “cycle beating” that clearly connote illegal attempts to defeat the testing procedures used by regulators.