I drive an unmarked '22 Ford PIU equipped with Whelen Inner Edge FST lightbars in the windshield. The lightheads are very visible when off, so to make it less obvious it's a police vehicle I'm getting a tint strip across the top of the windshield. The only other front emergency lights are high beam wig-wags so I don't want the Whelens to become too hard to see on a bright day. What tint percentage would be recommended to make the lightheads almost completely unnoticeable when off without impacting their visibility too much when I need to run code?