>    You guys are going to love this one!

Eeeeek!

What RPM? or speed? any idea, it shouldn't have overrevved, the FI would
shut off the gas nicely (BTDT), and the engine braking should be sufficient
to prevent runaway I presume...  so I'm lost.

I'm guessing the clutch disc had a lot of cracks in it, and finally let go
at higher but normal RPMs. If you look at some pieces where they broke you
may be able to see 'beach marks' like the sand ripples on a beach.  These
show the growth of fatigue cracks (like tree rings)  The surface appears
dull gray, where the metal has been progressively parting.  Once it lets go
the metal should appear more jagged, since it's tearing apart fast.
Finally, if there are small areas silvered over this is where the loose
pieces have been bumping into one another.  So, longterm slow failure should
show beach marks + tear zone (maybe +silvering), quick failure is tear zone
only. Any chance the pilot bearing in the hub is out to lunch too? Although
this is not attached to the disc it keeps the shaft/disc centered and
spinning properly.  It _may_ be a factor.  Keep us posted, this could've
been real nasty shifting from 3rd to 4th on the highway at 55+mph!!!!
Thanks, glad no personal damage.   tim