I love the dX6 and dX9s in my Toyota but alas I can't have the same setup in my Honda. I have to use EX602a in the front door. What is the best matching 6x9 to use in the rear?
By the way, the best material I have found for fabricating adapters is fiberglass reinforced plastic, FRP. It is easy to cut and very dense so it won't vibrate.