We don't get the Torsen diff on our GT PP, but yes probably driveline as both manual and auto boxes do it. It isn't a vibration at all, smooth as silk, just a minor noise.
Of course sounds buzz around a car pretty well so it could just be something at the back of the engine 'reflecting' into...
It definitely comes from under where the gear lever / shifter is. Not very loud and I assume it is just a normal noise.
It is more a tapping than a rattle and goes off when you ease off the throttle. It's a bit like gear thrash / backlash in that respect.
You need a smooth bit of road to hear...
Yes mine does that, more so when hot. I'm not sure it is a rattle, just something in the transmission?
7k miles on mine without any issue.
Oh, and mine is an auto so maybe not the transmission, maybe something nearby.
Maybe somebody should tell him. After all he previously said it was 'easy' to change an EU car to a US tune, only it isn't actually possible never mind easy.
Actually it is far more clever than that with the Toyota (and other hybrids) including those with an ISG where the position the engine is at when it is off is pre-determined to make restart easier and consistent, unlike a start from a starter motor which just has to deal with what it finds from...
There are plenty of post on this thread with actual evidence.
I can assure you hybrids do not 'spin up their engine' before starting as that would actually significantly harm fuel consumption spinning an engine with no fuel going through it with mechanical drag. I drive a PHEV some of the time...