There isn't really much that goes wrong with Subarus. The HG thing was chalked up to poor quality machining on Subaru's part, and they just use "conditioner" (stop leak) as the fix. Basically, you put in some conditioner any time you do a coolant flush. Subaru will warranty the HG for 100k miles and 8 years. Any major issues will be covered by this. If it takes longer for something to happen or if it is significantly worse where stop leak doesn't cut it, then there were other issues. Body to body is the standard 3 year 36k miles, engine and drive train is 5 year 60k miles. As for maintenance, it's basic things. Plugs, fuel fliter, air filter, etc. at regular intervals. Do the timing belt at 100k. Don't wait too long on this. It's an interference engine, so if the timing belt breaks, you've broken stuff. The only other way Subaru engines fail is by user error, i.e. not checking oil levels regularly. These engines are actually very easy on oil (shear breakdown), but they do burn through some with hard driving and using a "thin" oil like Mobil 1 5w30/0w30. The engine will run 200k-300k as long as you aren't ignorant with it. The tranny is decent. I haven't really heard anything bad about the automatics. Everyone whines about shifting, but that's kind of unavoidable when you aren't in control. There are some minor annoyances that Subaru seems to have some reflashes for to make the tranny shift better. I don't know any of the details, I'm a 5 speed guy. I don't know. These cars just wear well.
