Having just bought a 93' WRX, could any of you confirm if Subaru's generally have a subtle rumble/wine eminating from the rear Diff/rear of car.

This is more noticeable when the car is on over-run i.e running down hill on the engine.

Any help would be appreciated

 

I have a MY93 but I don`t experience the "whine" you have.
what sort of mileage ?
when was the oil last changed?

 

I have also just bought a 93 WRX and don't suffer from your problem.
(56k miles)
Andy