headlight relay harness (NAC)

[BenediktRochow at oaktech.com]

I need to ground the high-watt relayed H4 conversion lights on my Caprice
wagon, and do not see any place particularly suited to that purpose.
So I'm going to try to put the ring terminals on mounting bolts for these
lights -
the holes in the sheetmetal are alredy there, but what do I need to do
apart from scraping the paint off the sheetmetal? Will dielectric grease
(where does oen buy that?) keep it from rusting? How do I keep the grease
from being washed away over time?
Are stainless steel washers on both sides of the ring terminal appropriate
for this?
(Should I use one of those little springy-toothed washers sometimes seen on
ground straps?)

In other words: I'm clueless, help!

thanks,
-G. Benedikt Rochow