Once the Crossfire is as old as the TT you will see just as many options for modding the Crossfire, if not more. Plus, the TT is producing 180 hp or 225 hp depending on which 4-cylinder engine you pick. These engine are both already turbocharged. You could add a bigger turbo, but the Crossfire engine just has more room to grow, considering it has a displacement almost twice as big. Now the new upcoming 250hp 6 cylinder TT might be different, but mods for this engine are going to be much further in the future, since it is so new.

Plus, we all know you prefer anything Audi/VW...