I always mark top and low end first.
And “performance” is a new point as I formerly considered only the acceleration, because a taxi is rarely going topspeed. But there are some cars that accelerate slow but speed up to amazing speed, so performance is appprox. 70% acceleration and 30% topspeed to be realistic.
Drivability is far easier, as this is mathematically easy, 72,6 is the highest score in the field, and 1% is 0,726. The Frunian has 69,1, this divided through 0,726 means 95,18, and 95 % of 40 maximum points are 38, so Frunian car gets 38.
This does not work if lower score is demanded, p.e. in consumption. I am doing this more or less over the thumb.
So this is how it already worked in the 1990 challenge from its basic principes.