Nissan Motorsport is confident a "procedural problem" rather than a technical flaw with its wheel-nuts is at fault for the disastrous pit stops that have cost Rick Kelly big points in the last two V8 Supercars championship 200km races.
And team boss Scott Sinclair says the dramas are an example of the ground the team still has to make if it is to become a consistent front-runner in the V8 Supercars championship.
The Jack Daniel's Nissan Altima driver was denied a potential podium at the UBET Perth SuperSprint when a slow stop to remove the left rear wheel put him down a lap.
Then in the double points Race 12 at the NP300 Navara Winton SuperSprint last Sunday his left rear wheel couldn't be removed at his first stop, leaving the hardest working tyre on the car to complete an extra stint.
Kelly went on to his Dunlop softs with 36 laps of the race to go and charged back into the top 10 after the safety car period. He then drifted to 11th late in the race as his tyres 'went off the cliff'.
It is understood team-mate Michael Caruso also had an issue with a tyre change at Winton, but it did not cost him time.
Having also scored his first podium since 2011 the previous day - a second in race 11 after qualifying fourth - Kelly now runs 10th in the championship.
Kelly's strong form was reflected by Caruso who bounced back from a difficult start to the season to achieve third, fourth and 10th places, while Rick's brother Todd posted a fifth in the weekend's opening race 10.
In 2013 Ford Performance Racing (now Prodrive Racing Australia) suffered a string of tyre change disasters because of jamming wheel nuts, but in that case the problem was eventually traced back to a design issue.
But Sinclair says Kelly's problems lie elsewhere.
"I think it's more of a procedural problem than a problem with the wheel nuts," he told v8supercars.com.au.
"We obviously had good car speed but we let ourselves down with a couple of things that cost us on-track and a couple of things we got away with - which were disappointing - that happened inside the garage."
Sinclair said the team was aware of its issues and was working to rectify them.
"We are confident in where we are at. We know what we have to get better at so that is the easy bit and we constantly analyse ourselves and look at where we are weak.
"We are confident we will get there, but we are not there yet.
"We are realistic, we are not at that level where we are capable of winning week in and week out and that's where we need to get to," added.
"It was nice to run with the front guys last weekend but we showed again we still have a lot of work to do to make sure we can compete with them consistently.
The team's development of the Altima has been painfully public. It has twice re-homologated its aerodynamic package and is now awaiting a significant engine upgrade that is scheduled to flow into the four-car squad in the second half of the season.
But even as it waits for more power, Sinclair made the point the team's overall performance was continuing to improve. While Winton is a track where the Altima consistently performs well, he also pointed out that the team's performance in Perth was better than expected.
"I think our average qualifying position at Winton last weekend was 9.9 or something like that and the last time we were in the top 10 was the grand prix last year. So it has been over 12 months since we had a performance as strong as this so that is encouraging," he said.
"We all know how much the competition has lifted, but we have started the trend forward in terms of our results so we are happy with that.
"We left Perth with a little bit of positive because 12 months ago in Perth we were absolutely nowhere. And this year we found some good gains in set-up at Perth so we were more competitive."