So I looking to build an first gen MR2. If any car is a notch back this is one of them. Now the rules are written as such.

"Cars with a wagonback/notchback/
hatchback style body may have the rear wing assembly,
including the end plates and any wicker, mounted a maximum
of 4.0 inches above the highest point of the roof. For this
subsection, a wagonback/notchback/hatchback style body
(or variations of these) is a car in which the rear edge of the
roofline is no more than 28.0 inches forward of the rearmost
bodywork as measured along the vehicle longitudinal centerline"

my question is where did 28" come from?

where is the the rear edge of the roofline? above the rear glass? where the pillars meet the body work? does rear most body work include bumper?

thanks.