if I may just add my 2cents in here with regards to the plate...I think the plate is necessary because of two reasons. One it helps keep the incoming air directed to the intercooler, and two, I think it helps absorb some of the heat from the engine and turbo, instead of the intercooler absorbing all of the heat. ...just my thoughts, nothing scientifically proven. (cheers)
theoretically, I agree with you, but I respectfully counter with the following:
1. I have run it both ways and could not tell a difference.
2. The plate is bolted to the intercooler. Any heat absorbed by the plate would instantly be transfered to the intercooler.
3. It isn't worth the aggravation of the firewall whacking for the 1 extra horsepower that you may or may not be getting without it.
4. It looks way cooler without the goofy plate!