Here'* the reply I received today from Ellis at MagnaFlow:
If I understand your question correctly, you are looking for a universal converter and are wondering if you need an air inlet or not.
Your car comes with one stock, however you can seal that tube up, and install a universal converter such as a 94006, or a 94206.
If you want that mirror finish on your convverter PN 94306 will suffice.
If you are in the market for a direct fit, part number 23223.
I hope I answered your question, and if not feel free to contact me or ask again. Thanks for your interest in Magnaflow Performance. -Ellis"
My choice would be the mirror finish, just because...
Fast answer and good PR
Those numbers and links above show what he was talking about.
Hope this helped.
That'* what I found out.