Is the turbo on the MY03 WRX water cooled, and if so does this reduce the need for turbo timers, or letting the car idle for a min or so before switching off the engine?
Tom

 

Yes, yesish. Good practice is to drive gently for the last mile or so which does a better job of cooling things than idling.

 

Dunno about it being water cooled but it is oil cooled and as oil seems to dissapate heat better than water (which vapourises at 100 deg C) the oil does a better job
I would do as John says, run the car easy for the last few miles and either get a turbo timer fitted or just idle the engine for a min or two when you get home (gives you time to fit the disklok etc )

Tony