Owners of Volkswagen, Audi, and Porsche 3.0-liter V-6 TDI diesel models will remain in limbo for at least a few more months, it seems.

While a settlement covering 2.0-liter 4-cylinder TDI models received preliminary approval at the end of last month, progress on the V-6 cars has moved forward only slowly.

At a hearing Thursday, U.S. District Court Judge Charles Breyer—the judge also overseeing the 2.0-liter TDI case—set a date for the next hearing at which Volkswagen and U.S. regulators will update him on the status of the 3.0-liter settlement.

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But that hearing won't take place until November 3.

At roughly 85,000, the number of vehicles sold in the U.S. with the V-6 diesel and illegal "defeat device" software is far lower than the 4-cylinder group, which includes about 450,000 cars.

Vehicles equipped with the 3.0-liter diesel V-6 include five different Audi models—A6, A8, and A8L TDI sedans; the A7 TDI hatchback; and the Q5 and Q7 TDI sport utility vehicles—along with the Porsche Cayenne Diesel and the VW Touareg TDI.

2015 Porsche Cayenne Diesel

2015 Porsche Cayenne Diesel

Last month, the California Air Resources Board (CARB) rejected VW proposal for modifications to these vehicles that was submitted in February.

As with the 2.0-liter 4-cylinder cars, both CARB and the U.S. Environmental Protection Agency (EPA) must approved any proposed emissions-related modifications for affected TDI models.

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In a letter regarding the proposal, CARB said Volkswagen's descriptions of its proposed modifications were "incomplete, substantially deficient, and fall far short of meeting the legal requirements to return these vehicles to the claimed certified configuration."

Regulators haven't approved modifications for the 2.0-liter TDI cars either, meaning owners will have to continue waiting for a resolution even after the settlement for those cars receives final approval.

2014 Volkswagen Touareg TDI

2014 Volkswagen Touareg TDI

In addition to modifications, any proposed settlement for the 3.0-liter V-6 TDI models will likely include a buyback provision, similar to the one offered to owners of 2.0-liter 4-cylinder TDI cars.

Payments would likely be determined using a similar formula to the 2.0-liter TDI models, based on their trade-in value before the scandal broke.

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The 2.0-liter TDI settlement still requires final approval, which can only come at an October 18 hearing in front of Judge Charles Breyer.

Only after that point can Volkswagen begin making offers to buy back cars, and initiate a modification campaign, assuming modifications have been approved by then.

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