Tailschwing:
On a separate note, I find it really hard to judge the tailswing on 26t vehicles when looking in the mirror - it can be two feet clear and look really close. I think an hour driving around a rec yard in an old wagon which I could bump would really help because if I knew exactly what “too close” looked like it’d be easier to judge from a point of reference.
If you drive a regular truck then is it possible to put a marker on it which, when looking through the mirror, shows you where the rear is on the ground 
This is often done on training vehicles