say we have a 5th/6th gen platform (suspension and such) when traveling at high speeds (even at 75 mph/120 kph) the slightest wind will really throw the oem civic around

my guess is the oem suspension has the ride too high up and you need more low

but besides dropping height, what other things can be modified to increase stability of these econoboxes?

need more weight in the four corners to equally plant all 4 wheels into the ground

im talking extreme race car platform, the type of characteristics of an automobile that is properly suited for traveling at speeds excess of 200 mph

 

diffusers/splitters, canards, wider/stickier tires all that fancy stuff, just look at track cars, all the aero stuff that goes on. heck I even have f/r splitter on my time attack car and no I don't see super high speeds it just helps.