I am in New Zealand and have a 1997 Mustang GT convertible.Stock springs lowered 1", Bilstiens rear and Munroes front,otherwise stock. Problem is it rides so harshly it nearly shakes my bowels loose. Its a convertible so no racing or powering up,street only.What suspension would soften the ride? Would going to coil over do it? It was harsh when completely stock and also when we had lowering springs in it. Can't seem to find a formula to soften the ride.