Does anyone know if the headrest from a standard s type is interchangeable with the power headrest on the R’s or are they unique to the R model?

 

The actual headrest I assume would be interchangeable. The STR has the mechanism built into the seat back that electrically raises and lowers the headrest.

 

The cushion and frame are interchangeable...the cover is also interchangeable.....kinda tedious to do, but worth it....i used a regular s type unit and put it on my r power lower frame....i believe 2005 to 2008 are the same...just check part numbers

 

I did the same. Twice because I screwed up and installed the cover backwards.

yes it is a royal pita to remove and reinstall the cover