Adding Kevlar to cockpit floor or seatpan?

After seeing first hand the eggshell strength properties
of glass cockpits when they hit objects, I have been
thinking about how much protection I don't have between
my spine and terra-firma.

I have the astronaut foam, and otherwise it is just
the seatpan and glass. I was chatting with my A+P
about this while we had the seatpan out during my annual.

Has anyone contemplated and/or added kevlar to their
cockpits? Or is this just a nutty idea? I assume
their would be a weight and balance issue, and also
determining if the layup would in fact to any good.
Comments?