(1)I am almost closing a deal in buying 2005 Legacy GT. So, about extended warranty, aside from following maintenance schedule, (a)what should I be aware of so that the extended warranty wouldn't get revoked? (b)Also, what should I be aware of so that manufactures warranty wouldn't get revoked, if that can happen? (c)Can doing oil change at a place other than dealer rise to revoking manuafacturer's warranty or extended warranty revoked?
(2)A thread I saw today about head gasket reminded me of the thread I saw a while back about head gasket in Subaru. Though not specifically about the turbo, I read up on how the car engine works at "How Stuff works site". (I have seen the parts of an engine last fall when I joined an automechanic class though i didn't stick around till th end due to time constraint); I plan to educate myself on how everything works in my new car. What symptoms should I keep in mind to detect head gasket problem?