Erebus Motorsport and Ford Performance Racing are tonight undertaking major rebuilds following accidents for Tim Slade and Alex Davison in Bathurst practice.
Both drivers crashed heavily in separate incidents, with the extent of the damage casting doubt over whether the cars will be fixed in time for Friday morning's fourth session.
Todd Kelly also shunted his Nissan on Thursday afternoon, but the Altima escaped with minor damage after the rear-end broke loose at Reid Park.
The debut of the Car of the Future at Bathurst saw all teams chasing set-up throughout the opening day of running.
“It's not the day anyone wanted to have,” a distraught Davison, whose car clouted the wall at Reid Park, told Speedcafe.com.
“I was struggling with the car and then I crashed it. I made a mistake and crashed the car, it's as simple as that.”
Slade's HHA Erebus Mercedes had minutes earlier endured a heavy frontal impact with the concrete wall at The Cutting after the Gold Coast driver made a mistake of his own.
Crash sensors aboard the E63 AMG measured the Slade impact at 33 g-forces.
The Erebus team does not expect to know if it will be able to continue in the weekend until late tonight.
“The entire Erebus Motorsport crew has been climbing over the car and working feverously to try and get a true estimate of the damage,” said Erebus CEO Ryan Maddison.
“There are still several processes we have to go through until we can make a decision on whether we will have a car that can be fixed in time to be safe and competitive. Obviously, one of the things we mindful of is that his car also has to be at the Armor All Gold Coast 600 in 10 days time.
Added Slade of the crash: “I think it's broken the steering (after clipping the inside wall) and then its gone straight ahead.
“You feel so awful because you feel for all the people who put all the hard work and effort into this. They are the people who have to fix your mistake.
“You don't have a hit like that and get away lightly.”
The Erebus team had already scrambled to fix the HHA Mercedes in time for Practice 3 after a brake failure had pitched co-driver Andrew Thompson into the wall at The Chase during the previous session.
Like his rivals, Kelly had been struggling with set-up on his Nissan before clouting the wall.
“The car was ridiculously ugly in that session through there and that was going to be the last lap before we came in and changed to a different set up,” he said.
“I didn't want to try to drive it down the hill to get it back with bent steering,” he added.