Not to bring the subject back from the dead, but my falkens make a bit of noise a little before the limit of adhesion, and my all-season craptacular tires made tons of noise way before limit of adhesion. Too many variables to say when/why tires make noise. I'm pretty surprised though that your Subie drivers on street itres don't make a ton of noise. They usually make a lot - and a distinctive - noise.

As for the A/C, it does suck power. Parasitic drag can help those who think since they're racing, they need to be fast all the time.

germ makes a good point, but maybe not something to worry about for a first-time. Took me a while to realize just how much brake I really had.