boosted, sport-shift auto here, for about year and a half (25k kms or so).
impressions, p5 is a diff car with the extra power. Would it be better if i could run 8-10 psi daily and not really worry about the tranny? YES. I run about 6.5 psi daily. I'm not hard on it, i usually don't end up hitting 6.5, but occasionally i do... and it's nice. I haven't put synthetic in yet. i have a trans-cooler sitting at home. (mind you i boosted when it was like 30K kms on it).
What has a year and a half of turbo done to the car? well, so far it's been good. it'll start to slip if it's more than 6.5 psi, and I let up off the gas between shifts - which IMO makes a big big diff in the longevity of the trans. I control the shift points and if there is boost being forced on it midshift. I think that's why it's been good so far. I've tried driving it in regular "D" position a couple times to see how the ecu liked it. The stock shift points suck, and unless you are flooring it, the trans will try to shift on you at inopportune times.
If you are going to upgrade your auto-trans, i am thinking that an upgraded torque convertor as well as upgraded valve-bodies are gonna be in order.
btw i'm running the hiboost kit with the haltech f10. (was deckedoutmp5's kit - probably one of the first kits on this site aside from pirana's)
worthwhile? for what i expect from it - yes. are there better cars with more power yadda yadda yadda.. of course. But for what i have right now, this is fine. Just know that it's stressing the factory parts into less life than they would ahve had and be prepared for little problems.
hope that helps.
