I don't think this is a simple fix; rather I think it is a suspension engineering flaw inherent to the Continental product line. Wheel sizes and tire designs may have some influence but it is more than that. I experience this sort of ride harshness in my Reserve on 19" Michelins. This is the single worst aspect of this car. For a while, I had been thinking that I had been spoiled by my long string of Mercedes-Benzes but now I think it is more than that.