In the States, I'd make sure my registration and plate were current. Cops are not stupid, they all read English, and they are trained to look at such things. Of course, I used to wander around all over the place with expired plates and inadequate papers, and mostly I got away with it. It's merely a matter of risk assessment and dumb luck (or absence of luck).
In Latin America, I've been traveling for 8 months now without ever showing my current registration--I'm using one which has been expired since last fall. It buys me insurance, gains me entry at borders, satisfies soldiers at roadblocks, and in all respects does just fine--no bribes, no negotiations, nada. Yesterday, a customs official studied it carefully, correctly identified the effective date but somehow did not read the adjacent expiration date, clearly printed there for all to see. I haven't even thought to look at my plate to see if my sticker is current (under its normal coating of red mud and dust), but I wouldn't be the least bit worried if it's not: I'd just tell them it's good for two years, or whatever.
Note that I do carry current registration, just in case...but I haven't had to use it yet. I'll pull it out when I get back to the States, where such things seem to matter more.
Hope that helps.