Hmm wow I totally forgot about this thread.
I installed a Schroth White Tiger harness for my last track session (last year). Worked like a charm...held me down pretty well. Not entirely sure of the safety aspect though, but it did what it I wanted it to do.
Installed the harnesses to stock seat belt locations except for the left side...I couldn't figure out how to take off the plastic so it's bolted on to one of the bolts holding down the seat. I only use it for the track right now until I can get the time to disassemble the chair.
Front seat installed.
Sorry I don't have that many pictures...didn't take the time to document the install.