Driving cross country with expired tags - how to avoid police?

I've never been pulled over (they never had a reason to)

I'm about as law-abiding as they come, but it's still possible to come
under police attention due to bad luck or whatever.

When I was a college student, I was driving back to my dorm when 2
police cars boxed me in, and the police stepped out with their hands on
their guns. Turned out that a violent felon had just been spotted in
that neighborhood in a car similar to mine. After being frisked and
locked in the back of a cruiser for several minutes, the police
realized I wasn't the guy and apologized, but obviously it shook me up.

A more recent (and much less dramatic) incident occured about 5 years
ago, when a highway patrol officer followed me closely for about 10
minutes for no apparent reason. (Yes, I'm sure he was following me.) I
assume he was running my plates, but I have no idea why as I wasn't
speeding or anything. Probably he just picked me at random.

My point is that you never know when you might come under police
attention. Even good drivers can have it happen occasionally.

Jim