has anyuone ever sprayed an engine compartment w/ linex or rhino lining and then put bilge cote over it. Or have any suggestions

No, but it sure sounds like a neat idea though.

Perfect application for it. Go with Linex. It is a much superior product. You can pretty much get any color you want.

line-x goes on hot so not sure if that is a good idea.

if you can get them to do a thin coat of it i think it would be a good idea.....other then that i think it may add too much xtra weight...i know i felt a difference in my dually when they coated the bed with a thick coat of that Line-x stuff.......great material though