I have new MM/Bilstein coilovers up front. 10"/300lb springs. In the rear I have new Bilstein shocks and Eibach drag springs. When I drive, car handlingis great. If I hit a mild to large dip in the road though, I feel a "thud" like Im bottoming out. Are the Eibach really soft? Im thinking maybe since they are "drag" type springs, they allow the car to squat easily on launch at the strip? I think I need a stiffer rear spring set.