For the CFD test it may be easier to pick someones as a standard.
so everyone must use the same dimensions for engine, gearbox cooling and air intake fule.
everything else down to F1 rules.
solid boxes could be placed inside the standard to represent these parts.
these parts can be moved but the size cannot be edited.
and create a standard file format. for whoever is running it.
based on whatever app they are using.
if someone has an old car made, maybe a basic car before you added dd wings etc.