To all my friends please have a Merry Christmas and a happy 2021! After all that measuring, and dragging at your crash scene, remember the A and B stiffness coefficients do not involve any fundamentals. If the crash test is wrong, so is your A and B value. F= ma is fundamental,
f = drag force/normal force is not. It is only the Definition of f. Please, read the preface to the 7th edition, it's only you that counts that the jury will relate to, their trial. Be careful
and take care of yourself.

Best wishes
RudyL