When it was clear McLaren had missed its targets for the start of the season, it decided to roll out a three-pronged upgrade plan to get the MCL60 to the level the team believes it should be, having debuted a draggy specification in Bahrain.
The first package of updates was launched in Baku, and while the team was satisfied it produced the expected results and correlated well with its wind tunnel data, the car still proved excessively draggy and off the pace compared to some of its midfield rivals.
Earlier this year Stella revealed that McLaren's biggest upgrade package for 2023 was readied for launch before the summer break and amounted to "kind of a B-spec".
That substantial revamp has now been signed off by the Woking team's design departments and is heading for production, with a planned rollout at either the Austrian or British Grand Prix in July.
Team principal Stella said the car would look "noticeably different" but would be an evolution of McLaren's current concept rather than a Mercedes-like change of approach.
"The plan is we need to get the car more competitive. We've now released the package which should be available between Austria and Britain, and this is what should take the car to a more competitive level," Stella said.
"It's progressing the car, evolving concepts we see as successful. It will be noticeably different to what we have at the moment.
Source: Autosport