The 2006 is my second SC430. I traded my 2003 for the newer model. I have owned many proformance cars including Porches, BMW's, Mercedes,Ferrari and Corvettes. It is not the quickest or the fastest, but is definately the most comfortable to drive, especially on long trips. I enjoy owning this car.
Navagation system is great. Seats are very comfortable. Steering is easy. Taking the convertable top down is a snap.
Run flat tires are very expensive and only last about 15,000 miles.