This subject will always be personal, and subjective regarding context. After researching wheels for 3 months, I decided to stay with the stock 20' wheel, but increased to a 20x9. I stayed with the 20' wheels for a myriad of reasons from performance issues, to weight, to what was best for the overall fit & finish of the cars looks.
A hub-centric wheel was a MUST, as was T6-6061 aerospace aluminum, for the build materials.
I chose these, and love them...6 weeks custom build time
