I have cops in my family, plain clothes cops will leave u alone unless you are driving like a dick.
Traffic cops are the only ones which will yellow sticker cars as they are trained to look for defects such as too high/low lifts, incorrect rim and tyre sizes, noisey exhausts, illegal engine mods, the list goes on.
In perth the most common areas cops target are the weight bridge in guildford, great eastern highway and most car cruises where you get large quantites of modified cars.
If you are gonna lift your nav, fill the gap with some rubber and the cops will look the other way