I don't consider the hard top as a modification to the spyder, it is a factory accessory. It does change the looks, IMHO in a good way but makes if less versatile as a convertible. Once you are on the road it has to stay on. For me the number one point of the spyder is that it is a convertible, second a mid engine, third barrel of fun at low cost. I actually prefer the looks of the first Miata but it is just a bit to small for me on the inside.To correct myself: A hard top may be the only body modification that would likely always hold or even raise its resale value, especially if the convertable top is retained.