[forzaferrari]

McLaren will be allowed to make “necessary changes” to its 2020 F1 car when it changes power unit for next year, despite teams agreeing to freeze their chassis designs for next year.

Formula 1 has postponed the introduction of new rules which were intended for 2021 and agreed teams will continue using their 2020 chassis next year as a cost-saving measure following the disruption caused by the pandemic.
However McLaren had already agreed terms with Mercedes to switch to its power units in 2021. It will therefore need to make compromises to a chassis which was designed to accommodate a Renault.

Team principal Andreas Seidl said they "support the change of rules" and "we will be allowed to changes its MCL35 chassis in order to fit a Mercedes to it."