I just go 1 layer
I then use a layer of duct tape on the outside edge of the corflute to seal the whole thing around the edge to the window
Chester, two questions if I may...
1) what thickness did you use? Bunnings have 4mm as their thickest.
2) do you cut the corflute smaller than the window and ductape to the actual glass? (as that seems to be what is suggested in the link that Bird suggested) Keeping in mind that we're in a 105 cruiser with a tailgate, not barn doors.
or do you corflute to the window seal and then tape onto the actual tailgate steel?
Asking as I'd rather do this once and get it right.