I know someone in NM that runs them front and rear with no issues and does not carry his normal tags with him. He even has is sticker on them.
2001 Focus ZX3-Ours Sitting in the driveway, molested by the shippers
2010 Renault Clio 1.2 16V in Germany-Hers FOR SALE
2004 SVTF EAP/ST170-Mine
2013 Focus ST2 TS NAV SUNROOF-Hers