I have always felt more comfortable using an adjustable grill block with an aftermarket digital water temp gauge located in the outlet hose of the radiator. This allows me to control my water temps between 180 and 190 degrees at all times without the fans coming on and adding gas robbing electrical draws (about 12 amps on our Hondas). We run without alternators, so managing a 12 amp draw really extends the miles between grid charging the 12 volt deep cycle batteries.
Being adjustable, I only have to open it the minimum amount for cooling and get the maximum amount of aero benefit possible.
Here are the shutters behind the decorative grill on the 02 Insight. They are made from .090" aluminum sheet.
Here are the shutters open.
and closed
with the bumper, but before the grill was installed.