Fuel gauge wiring question

IVr has just been ordered.
Question, the RTE instructions state to mount it to one of the circuit boards grounding points, but up in post #5 by CFD244, it looks like it is just attached to the plastic body of the panel, would this make any kind of a difference?
My IVR is mounted to the metal gauge housing, which is where the circuit board gets grounded. The hole was there, and it was convenient. :)