Intermediate shaft bearing failure is always a possibility and effects both the 911 and boxster engines but failure rate's are not that high. Google it and you will see lots of results but you get plenty if you search for BMW swirl flap issues or Rover head gaskets etc.

With every car you buy you take a risk.

LN engineering do a ceramic upgraded bearing for $600 so its not the end of the world to get it sorted if it bothers you.