Putting the car in Park while moving

up to gen 4, around 6 or 7 miles an hour, but i'd advise against it. they put some buttons in terrible locations.

 

I did it backing up attempting to close my garage door. It just gave a warning, if you want to perform emergency stop, hold button or something to that extent. I know it didn't stop the car, perhaps it went into neutral.

 

Previous Prius generations were well protected against damaging user error in mis-selecting Park and Reverse. I'd be quite surprised if Gen4 went backwards on this.

Highway speed Reverse and Park attempts produce the same warning and result -- instant Neutral with a double beep warning.

I've occasionally practiced shifting to Reverse at highway speed ever since the Sudden Unintended Acceleration scare of 2010, as a faster way to get into Neutral than the delayed shift lever. A reflexive Neutral was one of two things that saved me from damage in a previous car, when extreme fatigue led me to commit a driver-induced SUA while parking. The Prius is our only household vehicle without a manual clutch, so something else is required to disengage the propulsion system.

 

A traditional automatic shifter is less error prone, both for accidentally choosing Park, or forgetting you're in Reverse?

 

Perhaps, but then it would possibly preclude auto-park at power-off, which you might consider an important safety feature.