What do I want in a CAI....
Most Importantly--> Dyno proven, track proven increased performance documented in the current 3.5TT GDI SHO
black plastic construction to prevent heat soak... If aluminum or SS construction have a black ceramic coating, have good quality SS connecting clamps, and plenty of flexibility to allow for the huge torque roll in these engines.
True carbon fiber for any filter "boxes"
Eliminate the saxophone, but maintain laminar flow, separate smaller diameter tube to each turbo, small enough diameter to speed flow without impeding it. More rapid air movement=less heat transfer to air.
Extra source of "cold" air... Like the inner DS wheel well skin. Bungs for all sensors, etc.
But documented increased performance eclipses all other thoughts.
Just my $0.02