Hundreds of thousands of Volkswagen and Audi owners are now in their fifth month of waiting to find out when and how regulators will approve modifications to their diesel cars.

But there's another group that's been affected by VW's diesel-emission cheating scandal: Volkswagen and Audi dealerships.

They are now subject to a stop-sale order issued by the makers on all new and certified used models of any TDI diesel vehicle made by their brand since 2009.

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But as reader Joseph M. from North Massapequa, New York, notes, car-shopping sites are full of new and used diesel models offered not only by used-car dealers but by Audi and VW dealers themselves.

So what exactly are they forbidden from selling?

2015 Volkswagen Golf TDI SE

2015 Volkswagen Golf TDI SE

We reached out to Audi and Volkswagen for explanation.

"The stop sale applies to new and Certified pre-owned TDI models," said Audi of America's Brad Stertz. However, "it is still possible to buy used TDI cars [at dealers] that aren’t part of the officially sanctioned CPO program."

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Jeannine Ginivan from Volkswagen said essentially the same thing: "There is a voluntary stop-sale order for all new and certified pre-owned TDI models."

"The vehicles are legal (per EPA)," she explained, "and therefore dealers as independent businesses can sell used diesels--but not as VW-certified used cars."

2015 Volkswagen Golf TDI

2015 Volkswagen Golf TDI

"We do not recommend this, but cannot prohibit it."

In other words, the stop-sale orders imposed by Audi and Volkswagen are voluntary--and they don't apply to used TDI models at all if they're sold outside the makers' Certified Used programs.

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All of those vehicles will still be subjected to recalls for updates once the EPA and the California Air Resources Board approve plans by Volkswagen to bring them into compliance.

And uncertainty over how those modifications will affect both their fuel economy and performance remains the biggest drawback.

Consumer Reports tests 2015 Volkswagen Jetta TDI diesel in 'cheat mode,' October 2015 [video frame]

Consumer Reports tests 2015 Volkswagen Jetta TDI diesel in 'cheat mode,' October 2015 [video frame]

That's especially true in stricter states that may require proof that the vehicles have been updated before they can be re-registered at some point in the future.

But given what appear to be relatively low prices for non-certified used Audi and Volkswagen TDI models, there are likely good bargains to be had on these cars at the moment.

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If, that is, buyers voluntarily want to opt into the same uncertainty over the cars' future now being experienced by existing TDI owners.

We suspect few will.


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