Luke, per your recomendations, installed Potenza RE 730's from the Tire Rack. Am 100% satisfied with wet and dry handling. Also like the lip that protects the wheel rims from curb scrapes and give the tire an exclusive "look". Tire noise seems a bit on the high side. Are there quieter tires or are the 730's average for this type?

Also, should I run the 500SL spec inflations or have your tests indicated other settings? Perhaps this could affect the noise issue.