Perfect score = you've paid JDPower the invoice in full.
There is actually a mathematical equation for the score of the make:
Score = [(percentage of invoice paid/100)*4]+[Subjective feedback from 0-1 from JD Power Execs on Hookers and Blow]
An example: Your company only pays 80% of the invoice amount and supplies no hookers and blow to JD Power brass, then:
Score = [(80/100)*4]+[0]
= (0.8*4)+0
Score = 3.2
Perhaps you paid the whole bill AND went to the max on hookers and blow (Playmates and the finest flake) :
Score = [(100/100)*4]+[1]
= (1*4)+1
Score = 5
See. Completely scientific.