It has been asked on automotive forums nationwide; are the long rectangle European
license plates legal? Well the answer is Yes and No and is well debated.
The facts are various states do not require a front license plate and it is perfectly legal to have the European license plate (Europlate) on the front of your car. This has been confirmed with various customers and DMV agencies nationwide. There are some good sites out there on the states that do not require a front license plate; our last count is 19 states that do not require a front plate.
There are also various petitions that are trying to have the front plate removed one notable one is Washington States RCW 46.16.240 as written The first sentence of RCW 46.16.240 currently reads, The vehicle license number plates shall be attached conspicuously at the front and rear of each vehicle for which the same are issued and in such a manner that they can be plainly seen and read at all times. We would like that sentence to read, The vehicle license number plate shall be attached conspicuously at the rear of each vehicle for which the same are issued and in such a manner that they can be plainly seen and read at all times.
However what about states that require front and rear plates? Technically you would not be legal using a front plate in these states and the fines are from a simple fix-it ticket right up to large fines or possible even the impounding of your car. There are some good loop holes in the system for you European car enthusiast and here are a few we have heard of. (1) Bought a new car? Run Europeanplates front and rear until you get your plates! (2) Some states issue collector (old timer) plates that only need to be mounted in the rear; this opens up the placement of the Europlate in the front; we have confirmed this in Washington and Oregon. (3) Trip permits sometimes will work for a quick weekend show and would allow you to use plates for the time listed on the trip permit.
There are also various local and state laws that allow you to run European license plates for various reason; we would recommend walking into your local licensing agency and asking this question in person and getting this info in writing so you are not risking the possibility of a ticket.
I have also had some travelers stop by our shop that actually had there vehicle shipped to the US for a road trip and they had a special permit allowing them to travel on our US roads; pretty cool but had to be expensive.