More than a perk, the black Audi is a rolling advertisement for its occupant’s importance and impunity in a nation obsessed with status. Black A6s slice through traffic queues and scream down the emergency lanes of Beijing’s traffic-clogged freeways, sometimes with a flashing red light stuck on the roof or implanted in the grille. Ordinary drivers know better than to cut them off or complain, at least publicly.

To many, it is also a symbol of rot within the vast party bureaucracy and of a widening gap between the privileged and the common man. Public crusades against corruption and extravagance have been a staple of Communist rhetoric for decades, but to little avail; even Beijing’s fleet of police cruisers includes BMWs.

“There is no longer a need to appear humble,” Martin K. Whyte, a scholar of Chinese society at the Fairbank Center for Chinese Studies at Harvard, said in a telephone interview. “If you look at the leadership of Mao’s era, at the way they dressed, it was certainly in part designed not to awe the population, to try to prevent appearing overly grand. That’s no longer in the cards.”

Perhaps so, but the A6 now easily surpasses the old stretch Mercedes as an object of popular resentment.

THE masses’ contempt has only grown since then, fed by a steady diet of corruption scandals involving highhanded party officials. In response, the government proposed rules earlier this year that limited the price and engine size of newly purchased cars, and required sellers to spend at least 3 percent of their revenues on research and development. Almost all of the 412 autos that qualified were Chinese brands; the 383,000 renminbi ($61,500) A6 was nowhere to be seen.