HGF is most commonly caused by the water in the UK and coolant mix everyone uses here (50/50). Toyota had issues with HGF failures in the UK with the Hilux 2.4TD which they never had anywhere else in the world.
The air faults I put down to cheap ass owners not replacing parts when they are due. I saw a 95 P38 for sale which still had original airbags on it (according to seller). The owner saw this as a mark of it's reliability. I see it as a common problem in the UK, too many owners refuse to get vehicles serviced when they are due or parts replaced when a problem first develops, usually waiting for catastrophic failure first.
