The Newcastle 500 could be Supercars farewell to Holden after General Motors announced it would dump the iconic brand by 2021.
The unexpected announcement has left fans of the series shocked and a number of teams who carry the famous badge in limbo.
Supercars said the decision would not impact the 2020 season, which starts in Adelaide on Thursday, but did not comment on how the series would look beyond this season.
"Today's news is understandably disappointing for fans who have followed Holden's success in Australian Touring Cars and Supercars since its debut in the 1960s," Supercars said in a statement on Monday.
"Holden has been firmly part of the heritage of our sport and has helped shape Supercars to become the sport it is today.
"The Commodore will remain on track for the 2020 Championship season and we're looking forward to seeing it alongside the Ford Mustang once again this weekend when the 2020 Virgin Australia Supercars Championship begins in Adelaide."
The 2020 Supercars series features 16 Holden Commodores, including the factory-backed Triple Eight/Red Bull Holden Racing Team.
Triple Eight only signed a two-year extension with the Australian car brand last July until the end of 2021.
Supercars had expected Holden or General Motors to have an operational factory beyond that season.
Holden is set to work with Supercars about how to handle the brand's retirement.
"On our future in racing, we've made a commitment and certainly we need to sit down with our partners, Supercars Australia and certainly the Red Bull Holden Racing Team, Triple Eight, which we will do hopefully in the coming days, and talk about the appropriate transition," Holden chairman Kristian Aquilina said.
"But our intention is to still go racing in 2020 while we've still got Holden vehicles out there in dealers' showrooms.
"To the extent, about GM and its involvement in racing beyond that, that will be part of the same conversation."
Red Bull Holden Racing won both Newcastle 500 races last year after Shane van Gisbergen claimed race one and Jamie Whincup race two.
The Newcastle 500 is the final round of the 2020 Supercars season.
If Holden is to be no more after the event, it could shape as a huge tourism boost for the region.
Any sort of organised farewell for the brand, which is synonymous with the series, would likely attract huge interest among Supercars fans.
This year's event, the fourth held in Newcastle, will be on December 4-6.