[gumby79]

Dose the bow wake from the semis push you sideways or caus a rotation around the center of pressure?
Had a Hyundai Excel that would squirt sideways, (not rotation) just behind the rear bumper of a truck I would get sucked over tord the trucks wake. The trailer/ cab gap only had effect on heavy wind days (30+) As my front bumper would entre the bow wake tbe front got pushed(CP artificially forward) , at my door the force was square (balanced CP) at my rear bumper it would push the back out rotating my trajectory into the trucks path (witbout correction.) (Artificialy biassed ththe rear
Point is;
If its rotating a rudder, fixed or dynamic, balince the CP.
If its squirting sideways , then downforce would be the fix,

Unscientific methodology for testing center of pressure in Dynamic wind.
Place on blocks of ice in cross wind and mesure the side force applied to each wheel center .
clading the spokes
This was popular with bike raicers in the 90's but favor quickly went for profiled spokes over disk,less gain but still a gain in more wind conditions. The disk is better for always in ahead wind ,but roads never seem to cooperate. . If you find your CP off oneway or the other use the disk on the light end this may be what your looking for.
To get more out of the front a-arms without a rebuild/skin . Add a gurney flap.