Andretti-Cadillac is refusing to accept Formula 1's decision to lock the project out of the sport.
It was already known that the collaboration "strongly disagrees" with Liberty Media-owned F1's position - that Andretti can only make another bid to become the eleventh team in 2028, when a works GM engine will be ready.
But Jim Campbell, the motorsport boss at Cadillac's parent General Motors, insists that Andretti and GM are "continuing to develop our car at pace".
When asked to expand on that position at the Daytona 500, he stopped short of agreeing with a reporter that F1's rejection of Andretti-Cadillac is "insulting".
"Our joint teams are continuing to develop our car at pace," he insisted. "So, that is where we are at.
"We're not saying it's easy, but between our two organisations, we have examples of where we have been successful in other motorsports categories. We feel great about our application."
That application was accepted by the FIA, but fell short of earning the approval of F1's commercial rights holder or the vast bulk of the existing ten teams.
"So obviously they (F1) made their statement," said GM's Campbell, "and we have asked for a follow up meeting with FOM and so we will work through that."
He takes issue with F1's position that if a works Cadillac engine had been at Andretti's disposal for 2026 rather than 2028, the outcome may have been different.
"When you register to be a power unit, there is a deadline to do that, and for us it was last June for 2028," said Campbell. "So, it's simply a regulation.
"We feel confident in our application and are asking for a meeting with FOM," he reiterated.
