I am sure its also down to the regular servicing and maintenance of the car. I sure Neily this may be the case for. But I'm sure it a problem that can be fixed, just a common problem for less maintained older automatic cars.
My car has 114 k miles on and the auto box as well as the engine are very smooth and change very nicely, I don't just drive I count the changes, the overdrive works properly too, I am just looking back into the cars history to identify when the Oil was last changed, but its a nice colour. Honest John said its a nice tough auto box I've seen some have done 250k. What's yours done BTW.
I also have this "problem" on my T27 from 2010, with 137000Km. It's more like a subtle clanck than a click but it's there and it seems like a loosen screw somewhere. I've also, for more than one time, said to the Toyota garage about this and they came to me saying everything is OK and couldn't find any loose screw. On my side I find it, sometimes, when I turn to left. But, as all of you said, it's not always.
It's for sure NOT the issue for which some of the Avensis were recalled due to some issues on some screws on the steering área.
In fact it would be very nice to find what is that...
Yep, no turbo.
The petrol engine works on Atkinson cycle that, in theory, is more efficient but at cost of loosing some power.
Hope it helps.