The Florida Supreme Court has ruled drivers can be pulled over for any obstruction of their license plate. This can include large tag frames, trailer hitches, bike racks, handicap lifts, tag lights, wires, or anything that could obscure the reading of the plate. The statute reads “…all letters, numerals, printing, writing, the registration decal, and the alphanumeric designation shall be clear and distinct and free from defacement, mutilation, grease, and other obscuring matter, so that they will be plainly visible and legible at all times 100 feet from the rear…” The Supreme Court’s Opinion can be found here – https://www.floridasupremecourt.org/decisions/2016/sc14-2229.pdf