This week, a for a “Pre-Production 2021 Chevrolet Corvette Stingray Coupe C8.R 01EX.” In the comments, the listing seller tells a tale of a General Motors experimental that somehow escaped GM’s clutches, an unaccounted-for machine that, if genuine, would count as the 1,001st example of the , a special package commemorating the mid-engine Vette’s in . Jalopnik spoke with a Chevy representative to try and get to the bottom of the mystery.

The shows just 97 miles on its odometer. The seller, a Sarasota, FL dealer who posts on BaT under the user name “coolstuff,” explains in the comments that he bought the yellow Vette at auction in July and initially didn’t think it was anything special. Then he noticed a few unusual details: the bodywork showed traces of adhesive where racing stripe decals had been applied, then removed. Even more puzzling, the car wore an interior plaque that marked it as a one-of-1,000 IMSA GTLM Championship Edition.

But instead of wearing a serial number, the interior plaque said “01EX.” And when the seller noted this unusual plaque to his contact at GM, he claims the automaker representative replied in a panic, asking to take the car back to Detroit to be examined by Chevy. The dealer declined, but agreed to let a GM technician come to his facility to examine the Vette.

As the seller tells it, the GM technician spent eight hours going over the mysterious ‘21 Stingray. Most of the work seems to have been rather mundane: Adding legally-required warning labels and making sure the owner’s manual was correct for the year and spec of the car. But as the seller tells it, the GM tech characterized the Corvette as being an experimental prototype that somehow slipped out of GM’s hands and ended up in a used-car auction by mistake. From , lightly edited for clarity:

[The technician told me] this car was to be stripped and or crushed but it was not in the warehouse where the others were decommissioned, instead it was in the media building and got missed. There is an app on the car that is proprietary to GM that talks real-time to GM in Detroit, and it needs to be removed. Plus, this car was not supposed to be sold or on the road, so we need to make it compliant with all warning labels and replace the owner’s manuals in the car with the correct version. He went [on] to say this car has caused some S#@T at GM because there was only 1,000 C8Rs made and now there are 1,001! If they would have removed the plaque as they were supposed to, with all the other C8R stuff, you never would have known what you have.

Unfortunately, a quick chat with a GM representative painted a much more mundane picture. “This Corvette is special in a way,” Trevor Thompkins, senior manager for performance car and motorsports communications, told me over the phone on Thursday. “It’s a 2021 Corvette mocked up to look like an IMSA GTLM Champion Edition, which was only sold in 2022.”

Thompkins confirmed that the 2021 Corvette in the BaT listing was initially sold back to GM as part of the manufacturer’s Captured Test Fleet program. The CTF program is well known to GM enthusiasts, with explaining how it works. Basically, GM takes delivery of a fleet of pre-production vehicles and assigns them to company employees to use as daily drivers for up to 7,000 miles. The vehicles are equipped to send data back to GM to show how new model-year changes are performing under real-world driving conditions. When a vehicle ages out or miles out of the CTF program, the telemetry data communication system is removed, and the company performs any changes required to bring the pre-production car in line with a production-spec vehicle for that model year and sub-model. Then the vehicles are sold to the public through used-car auctions.

Thompkins confirmed that, based on the VIN listed on the BaT auction, the yellow Corvette seen here was formerly owned by GM as part of the CTF program. As the auction listing states, this particular Corvette was mocked up with the model-year ‘22 IMSA Champion Edition appearance package, and was driven to various racing events as a Chevy promotional vehicle. In fact, this very Corvette was the vehicle shown at the 2021 Detroit Grand Prix in June, where the 2022 Champion Edition package was first unveiled to the public. It was also used in promotional photos and materials published by Chevy.

“What essentially happened was, when they did the inspection, they left the [C8.R special edition] placard in there, even though the stripes were taken off and it was returned to the build status that matches the Monroney,” Thompkins told Jalopnik. “We make sure those vehicles match everything a production Stingray of that model year would have, and that’s a process that happens before it’s auctioned. That’s why the technician went out after the auction, to make sure everything was buttoned up.”

Thompkins confirmed that the CTF Corvette would not have had any special equipment installed that was not meant for production, and that any software that sent vehicle data back to GM would have been removed. As for the seller’s note about receiving a Monroney window sticker marked “Reissue,” Thompkins told me this is standard procedure after a CTR vehicle is brought back to its correct model-year spec. (Recall that, as a pre-production vehicle, this Corvette might have initially been built with equipment or software that did not make it into regular production, all of which would have been removed before it was auctioned to the public.)

So, yes, the BaT listing is correct, in a sense: This vehicle started life as a pre-production 2021 Corvette Stingray, and was updated to match the 2022-only C8.R special edition package. It was used by Chevy at racing events and photographed for promotional material. It’s doubtful, however, that this vehicle was meant to be stripped or crushed as the seller describes. Judging by what Thompkins told me, it sounds like GM’s technicians initially missed the special-edition badge in the interior when they set about returning this vehicle to model-year 2021 spec before selling it at auction; when the interior badge was discovered, the automaker sent a technician to check over the car again to make sure nothing else was missed.

So, is this one of those legendary top-secret prototypes that was never meant to leave GM’s hands? Unlikely. But it is a unique Corvette, one with a fascinating backstory and unusual equipment that makes it one-of-one. That seems to be enough to generate lots of interest: As of this writing on Friday, , a full $10,000 on the window sticker. The auction closes on Monday; we’ll be curious to see what the winner ends up paying for this Corvette of unusual provenance.

The Corvette auction ended with .