This is probably the correct answer. I drove around without a front license plate for over 4 years (my state requires front and back) since my car didn't come with screws for a front mount. It was one of those things I put on my to-do list but never got around to and eventually just kind of forgot about it.

Anyway, I live close to a couple of police stations (I live near a border to another city, so my city and the next city have PDs within a couple miles of each other) and never got pulled over. Hell, I have even went through several traffic stops over the years and none of them ever said a word to me. A few months ago I finally ran into a cop that actually gave a shit and pulled me over. He was obviously a new recruit, as he was very young and did everything very by-the-book. I got a warning and the next day I ordered a mount for my other plate, but I was just amazed I'd gone so many years without any cop caring. I figured it was because most cops just can't be bothered to care about small shit like that. Though, if I was a minority (I'm in the US), it'd probably be a different story.