New Mexico does not require passenger cars to display a front license plate. Colorado does. Can a New Mexican police officer cite a driver if the car they’re driving is registered in Colorado and is not displaying a front license plate? (NM and CO are just examples; I don’t care about those states’ laws specifically, but rather the concept in general.) (Also, I don’t care about how un/likely it is.)
If it’s not illegal in the place where the officer has jurisdiction, I don’t see why the officer would have any pretext for a citation.
If he has pulled you over for something else, he might tell you, “You should get that fixed before you go home,” but don’t think he is under any obligation to hassle you about some other state’s law.
If it isn’t against the law in New Mexico, a New Mexico LEO can’t do squat.
Police officers enforce laws based on the jurisdiction in which they serve, a Colorado or New Mexico police officer is going to enforce Colorado or New Mexico law, respectively. They will assist in apprehension, in some cases, of persons from other jurisdictions, but they aren’t generally going to enforce laws not extant in their jurisdiction–in fact they don’t really have the power to do so.
The only somewhat exception is that I believe most (maybe all) States allow their police to arrest people on suspicion of violating Federal law (even if there is no corresponding State crime), obviously the local U.S. Attorneys office would have to agree to prosecute for it to go anywhere though. A lot of immigration detainments are by State police on suspicion of someone committing an immigration violation.
Hmmm. I was once informed, here I believe, that someone driving a car in a state with no inspections but where the car is licensed in a state that requires inspections and what’s more the car has an expired inspection tag, could nonetheless be cited. It seems the same principle.
(Let me try that again. Vermont requires various vehicle inspections. Montana does not. Jones drives his VT-licensed car in MT, with an expired inspection tag. Can a Montana cop bust him? I was told ‘yes’.)
It’s going to depend on the 50+ jurisdictions.
In Wisconsin a vehicle registered in another state is not subject to our registration laws (341.40).
However the vehicle still has to be compliant from where it’s from. If someone from the flatlands comes up here and is missing a front plate I do have cause to pull them over as I know Illinois requires a front plate. A case regarding this went through appeals and confirmed what I just wrote.
In Washington, and I assume most places, you’re legal if you’re legal in your home state:
RCW 46.16A.160
Nonresident exemption—Reciprocity—Rules.
(1) The provisions of this chapter relating to the registration of vehicles and display of license plates and registration certificates do not apply to vehicles owned by nonresidents of this state if:
**> **
> (a) The owner has complied with the law requiring the registration of vehicles in the names of the owners in force in the state, foreign country, territory, or federal district of residence; and(b) The license plate showing the initial or abbreviation of the name of the state, foreign country, territory, or federal district is displayed on the vehicle substantially as required in this state.
(2) This section applies only if the laws of the state, foreign country, territory, or federal district of the nonresident’s residence allow similar exemptions and privileges to vehicles registered under the laws of the foreign state, country, territory, or federal district.
(3) Foreign businesses owning, maintaining, or operating places of business in this state and using vehicles in connection with those places of business shall comply with this chapter. Under provisions of the international registration plan, the nonmotor vehicles of member and nonmember jurisdictions that are properly based and registered in such jurisdictions have reciprocity in this state as provided in RCW 46.87.070.
(4) The director may adopt and enforce rules for the registration of nonresident vehicles on a reciprocal basis and with respect to any character or class of operation.
Cause to pull someone over wouldn’t in and of itself be enough to enforce the laws of another state. For a citation to hold up when challenged it would have to relate to something specified in Wisconsin code Chapters 349, 341, 346. There may be some violation in there for improper out of state registration, but I wouldn’t want to spend the time investigating if that is the case 
.
Wouldn’t be enforcing the laws of another state, would be enforcing the laws of this state when they match. There was a court case on that scenario as well but darn if I can find it. In reality I don’t recall ever having pulled over a FIB who had a rear plate but no front plate.
When it comed to plates the people I like to stop are these idiots who have a dozen registration stickers plastered all over the plate so it cannot be read. $174.50 pay at the municipal cashiers window.
Florida’s applicable statute requires both plates to be affixed if two are issued in the state, because heavy commercial vehicles in Florida get two plates even though everyone else gets one.
I’m not exactly sure, but I think @pkbites is saying that his state has a law (a sort of “meta-law”) that the plates must be compliant with the law of the state of registration?