OverRun:
The QAR on the aircraft I'm referring to was not accessible in real time, only by post-flight data dump. As to accelerometer position, I don't know.
We did have some early B767-200 on which you could display a selection of parameters in real time on a small LED screen near the back of the centre stand, and load factor was one of those available. I don't recall ever looking at it while on the runway, as there were more important things to do.
Your comment about using the airport manager's car is telling............