[quote=oyster_gold]Changing rear end gears and considering it "modified" is debatable depending on the car. In terms of the XF where no factory rear gear options were available then yes, I would consider a change in gears to be a modification, but if my Mustang came with 3:55's and I swapped them out for a factory option 4:11's than its still a bone stock car IMO. quote]

Can you get the 4.11's installed in the Mustang from the factory? I don't think so. Can you get 4.11's over the parts counter? Yes you can.
I know our cars say Chrysler, but there isn't one mechanical part in it built by Chrysler. But Mercedes Benz built cars with the 3.50 and 3.91 gear ratios, (installed from the factory) and you can go to "Their" parts counter and order one for your Daimler/Chrysler.
So going by your analogy Oyster, (by what should be considered "stock" and what constitutes a modification) at the very least, the Crossfire should fall into the same catagory as your Stang.IMO Why? because we all know we're driving a Merc.