The vast majority of affected customers has opted for a buyback.

Volkswagen has repurchased or repaired more than half of US vehicles powered by emissions-cheating 2.0-liter TDI engines.

The company has bought back nearly 238,000 vehicles, while just 6,200 have been repaired, according to a Reuters report based on a letter to a judge overseeing settlement proceedings.

The fleet includes around 475,000 vehicles, leaving nearly 231,000 still waiting to be repurchased or fixed.

The company has already agreed to pay tens of billions of dollars in US fines and penalties. The financial hit could increase if less than 85 percent of the offending 2.0-liter engines are not fixed or taken off the road by 2019.

Most of the vehicles affected by the scandal are older 2009-2014 models that have not yet received a finalized fix plan. Newer vehicles can be brought into compliance via a relatively simple repair, but the others are expected to require more extensive -- and expensive -- modifications.

As thousands of vehicles continue to arrive at several holding sites each week, VW could be pressured to scrap some of the oldest vehicles with resale values below the costs of whatever repair regulators eventually approve.