Doing 120 mph on the road is quite dangerous in a car that wasn’t really designed for it.
once you get over 100 mph, aero becomes a HUGE factor. Drag under the car can create life, which will cause the car to feel skate-ish and loose. You need to smooth out the underside, add an air dam up front, a rear diffuser out the back and probably side skirts. Maybe even fender chimneys
