So the rev limiter in the IS works differently than most all other automibiles? Typically - a rev limiter cannot help in a downshift situation as it only cuts off fuel supply.. which will NOT help in a downshift situation - where you already have your rpms up.

 

Any auto transmission that doesn't know not to go from 6th to 3rd at 100 mph isn't worth its weight in scrap.

Auto transmissions don't misshift like that, only people do with sticks.

Edit: I have never heard of an auto doing that. It may have happened....?

 

It will probably beep at you telling you that it couldn't do the shift, similar to how it does if you're in sport mode and keep tapping to downshift (into a gear too low).

 

Add to this I'm dead sure this engine will take 7500 rpm with ease. The only thing that might get upset is the valve springs. Certainly not the bottom end or the rod bearings.

There is no way you hurt your engine.