Just cause it doesn't work on audi's, doesn't mean it doesn't work.
Here's a dyno of a 6s before and After the CP-E intake/Maf Customizer.
This was done while the car was STILL strapped to the dyno, and the straps weren't changed. Dyno runs were subsequent, with the stock runs occuring on a cold car, and the CP-E run occuring after it.
One thing I've learned with cars, is no two cars are the same (dyno wise), nor are any two manufacturers cars the same (even if they use similar drivetrain components). Thus any mod that works on one vehicle type, may or may not work on another, so assumptions can never be made on their effectiveness until their tested.
On 1.8T's, cold air intakes won't make much difference, as their primary intake temps are directly affected by the turbo...in this situation most of the gains you would see from a cold air intake, are instead seen from aftermarket intercooler setups...which I'm sure your forums have shown variable gains in across the board.
As for the syn comments on power...yes your correct, its almost impossible to test. Thats why I pointed out the overall "average" baseline dyno's "across the board" are higher with car's running synthetic, then with dino based oils. Alot higher? No...but higher non the less.
I am merely pointing out that synthetics have other advantages then just extended OCI's and possible "extreme condition" protection. They do show a slight increase in power, and also show an increase in mileage. Especially if you do engine, diffy, and tranny oil all at once to syn.