FIG. 1 is a front elevational view of a vehicle testing instrument showing my new design;

FIG. 2 is another front elevational view;

FIG. 3 is a left side elevational view;

FIG. 4 is another left side elevational view;

FIG. 5 is a right side elevational view;

FIG. 6 is another right side elevational view;

FIG. 7 is a rear elevational view;

FIG. 8 is another rear elevational view;

FIG. 9 is a top plan view;

FIG. 10 is another top plan view;

FIG. 11 is a bottom plan view; and,

FIG. 12 is another bottom plan view thereof.

The broken line showings of a tank, wires, battery case, generator and pump in figure drawings 2, 3, 5, 8, 9, and 11, are for environmental purposes only and form no part of the claimed design.