Quick Question: Is this supposed to happen?
I’ve had steering go over the top before,what I was referring to is that once it gets to 55 MPH (ish) it oversteers and understeers dramatically at the same time 
Heavy understeer + catastrophic oversteer at the extreme is a thing and not a bug. What is weird is that it is coming back again then, that probably is not quite right and might be caused by numerical instabilities in the calculations. That’s nothing we’ll be able to fix easily though.
It is first going to +infinity and then to -infinity (in theory). The graph should be cut off before that happens, maybe the cutoff threshold is a bit too high (it’s currently cut off when the grpah is rising or falling at a rate bigger than x). Numerical stuff probably makes it not reach infinity “properly”.