Guys you gotta expect to be looked at when you're pulled over because the cars we drive standout from the norm and the cops know that we carry out mods.
If you don't bother getting permits who's to blame. I agree that they shouldn't give you any extra attitude because you drive an import, but remember they are human and will react to any attitude you show them.
When dealing with traffic cops be polite, your're on a hiding to nothing if you give them shit.
My understanding is that any mod has to be within the ADR guidelines (ride heights, noise etc) and technically should have a permit unless the mod is a standard fit to a model of car in the same range.
IE If you own a car that as an option had a larger wheel package available when new, you can fit wheels of that size without getting a permit. Always pays to check with licencing.
Insurance is another issue. HBF told me that my car will be covered as long as all mods are permitted by licencing.