Lots of good weight loss ideas.
Have you considered any AERO inprovements.
FOOD FOR THOUGHT
One I have seen is block off your grill area
with a thin sheet off lexan use the outer headlight bezel and grill trim screw holes to atatch it cleanly.
Drip rail shave would loose weight and decrease
drag.
Surface mount your front windscreen like old school nascar.
A chin spoiler is fairly light and they help significantly.
Aero or lack of it is a major loss. ANYTHING to decrease drag WILL increase your trap speed.
The way I see this thread is your weight loss will significantly help to 60' and to 60 MPH but after 60 MPH
aero is well a HUGE DRAG. Pun intended.
EXAMPLE
"Speed Increases Drag
Since drag depends on velocity squared, driving at 70 mph results in about four times as much drag as driving at 35 mph. Merely increasing speed from 55 mph to 65 mph increases drag by about 40 percent, resulting in a 10 to 15 percent increase in fuel consumption."from online source
I have read this thread completly and was inspired to add something positive to assist you in your endevor. GOOD LUCK