Re: Kumho 18
Yes, rear Kumhos will make the bottoms of your quarter panels look like they were peppered with bird shot. I will have to have mine repainted eventually. There is less damage to the upper rear fender area that surrounds the wheel wells. Those I've now got 3M tape on, which really helps. I just put my front Kumhos on and put 3M on all the painted surfaces I thought to be at risk.
The 3M is pretty easy to do, especially in areas where how professionally you apply it doesn't matter as much since it's not really that visible.
Here's my .03 on Kumhos (with inflation). How much damage will I do to my car when I lose it (like I did once or twice) shifting into third and the tail coming around and car going for the ditch at around 75-80 mph? These cars are just naturally tail-happy. Since I don't drive in the rain if I can help it, I have NO need for Michelins. They are dangerous on cars of this capability, imo. Maybe it's the 3.54s? Maybe I just have a heavy foot. But I have yet to break loose the Kumhos in 2nd or 3rd.
I would not recommend Kumhos in rain - they will hydroplane like crazy.
BTW: I ran rears only for a thousand miles or so and must report the handling is MUCH better with matched tires on front. I never got into a scary situation with Pilot Sports on front, but the understeer was exaggerated and I'm told by many people having different casings really is dangerous in extreme handling situations. Jon B was right in his advice - go with matched f/r.